Unit 4 Review

Wow we started this unit a long time ago!

Lessons 1 and 2

Lesson one introduces the unit and defines toxins as harmful substances that can harm and enter the body in many ways. Lesson two goes into the chemical equations of these toxins. Equations help scientists predict and track chemical changes.
Practice Problem
3A. A solid and an aqueous solution combine to form an aqueous solution and gas.

Lessons 3-6

Lesson 3 was about physical and chemical changes. A physical change is a change in matter in which a substance changes form but not identity.(Dissolving) A chemical change is a change in matter that results in the formation of a new substance with new properties.  Lesson 4 is about the law of conservation of mass which states that matter can't be created or destroyed during a chemical reaction. And then lesson 5 taught us how to balance equations, when doing so you can only change the coefficient. Lesson six went into further detail about chemical equations and classifying them into 4 major groups:
Combination: A+B => AB
Decomposition: AB => A+B
Single Exchange: A + BC => AC + B
Double Exchange: AB + CD => AC + BD
Practice Problem
3A. NaOH (aq)+ HNO3 (aq) => NaOH3 + H2 (l)

Lessons 7-8

Lesson 7 was about lethal doses, which is an amount of an ingested substance that kills 50% of a test sample of animals. (mg/kg) The smaller the dose the more toxic it is. Then lesson 8 was about percent error. There is a picture of the equation below.

 

 

Lessons 9-11

 

Lesson 9 talks more about moles. The mass of 1 mole is equal to the molar mass. Then on the periodic table the atomic mass is equal to 1 mole of atoms of the element in grams. You use molar mass to convert between moles of atoms and grams of atoms. Lesson 10 put our skills to the test and we had to make sure to remember to label our numbers with units and make sure our units cancel out.  And lesson 11 continued on with this theme so heres some practice problems.

 

Lesson 12-15

In lesson 12 we learned that aspartame is much sweeter than fructose. The smaller the LD50 the more toxic it is. LD50 values are of limited use in determining the long term effects of a substance. Even if you don't reach the actual LD50 there could be very serious long term effects that are not accounted for in the LD50. In lesson 13 we learned that a solute is a substance dissolved in a solution. A solvent is the substance in which a solute dissolves. ( A flute in a vent!) And that molecules in a high concentration area move to areas of lesser concentration. (Molarity) In lesson 4 we put our new found skills to the test.

 



 

 

Lessons 15-19

 

The biggest thing we learned in lesson 15 was that you can use a hydrometer to test the molarity of the substance. In this next lesson we basically used all the knowledge we've gained from throughout the chapter to solve problems. We also did an activity where we had to try and figure out which solutions were which by weighing them and accounting for the molar mass.

In lesson 17 we learned that an indicator is molecular substance that changes color when it comes into contact with an acid or a base.

Acids and bases are corrosive. When pH is 7 it is neutral or pure water. Below 7 is an acid and above 7 is a base. This is a picture of the pH scale.

These pH solutions are classified by their colors you can observe. Acids and bases change the color of indicators.

.

Lesson 18 taught us about cabbage juice and its indicator colors. Cabbage Juice: Pink=acidic, Green=basic, Purple=neutral. Substances that add H+ (just one proton) to a solution are acids. Bases are substances that add OH- to a solution. Substances that don't add H+ or OH- to the solution are neutral.

• Arrhenius Definition: An acid is any substance that adds hydrogen ion to solution. A base is any substance that adds hydroxide ion to a solution.
• Brønsted-Lowry Definition- An acid is a proton donor. A base is a proton acceptor.

The products of a reaction is always called a conjugate.

Lesson 19 talked more about the pH scale. The pH scale is a logarithmic scale the describes the concentration of H+ ions. pH is related to H+ by the formula: pH=-log[H+] Water dissociates into H+ and OH- ions. Below is a picture of the pH scale and examples of substances that fit into each pH level.

 

 

Practice Problems

7. The NaBr would weigh the most because it has more solute than NaOH. The KCl weighs half as much as the other two because, 500 mL is less than 1 L or 1000 mL.

1. A base is a substance that adds a OH- ion to a substance and an acid is a substance that adds a H+ ion to a substance



Lessons 20-25

Lesson 20 was about dilution. When you dilute something you make it either less basic or less acidic. 7 is the neutral number in the pH scale and by diluting a solution you can approach 7 but you can't turn an acid into a base and visa versa by dilution. We also learned that between each number on the pH scale there is a 10 fold. Then we learned about neutralization, which is when a strong base and a strong acid react and form ionic salt and water. We also learned that when two compounds have the same volumes and the same molarity they have the same number of moles. When this happens its neutral. Then in lesson 22 we learned that titration is the neutralization process between a strong acid and base. When a strong acid is mixed with a weak base there isn't enough OH- ions to neutralize all of the H+ ions so the solution will not be neutral. It will however, be closer to 7 than either starting solution. In lesson 23 we learned about precipitates, which are solids that are produced in a chemical reaction between two solutions. Sometimes The mixing of two ionic solutions results in the formation of a solid. The degree to which a compound dissolves in water is called it's solubility and precipitation is not limited to solids. Lesson 24 was all about molar ratios. A mole ratio is a ratio given by the coefficients in a balanced equation.
Lesson 25 basically continued to break down the mole tunnel and mole ratios into 3 steps. The mole tunnel is just the way you set up your equation to solve mole ratio problems. First, convert grams to moles. Next, find the molar ratio, and last convert grams into moles.  ANd finally lesson 26 was abput percent yield which is The equation for percent yield is the actual amount, divided by the theoretical amount and multiplied by 100.

Practice Problems

Disappearing Spoon - Chapter 15-17

Chapter 15, opened with a story about William Crookes. In order to take care of his extremely large family,(large group growing up and eventually had 10 children of his own, that seems like entirely too many if you ask me!) he wrote a book on diamonds and edited a science journal. Then the story moved to his brother and his life. He was known for spiritualism, and pioneering the study of selenium. When the brother died the chapter moved into pathological science is. The book then moves into a story about the Pons and Fleischmann. This was a family known for cheating. They created two protons and two neutrons of hydrogen gas. Instantaneously the two became famous and scientists all over had the idea of cold fusion.  As in any large discovery, many skeptics remained. It turns out their skepticism proved worthy. It was discovered that the family had overlooked many issues and had measured incorrectly. A protest against the family then follwed. The end of the chapter was about X-rays. Rontgen discovered the basics of X-rays, and later Henry Moseley executed these basic X-ray set ups.
Chapter 16 talked about tin in the beginning. Tin can turn carbon from graphite into diamonds, it becomes protean at 56 degrees F. Then it talked about temperatures and solids. Lastly, it talked about light and the first laser light. This idea was quickly thrown out after being deemed impossible by Niel Boher and Von Neumann. In chapter 17, a man named Donald Glaser, who invented the bubble chamber. He used a various liquids like as beer, hydrogen, and calcium for his experiments. Calcium bubbles have shaped economics and empires. Over time, bubble science became a respectable field because of the work of Ernest Rutherford and Lord Kelvin. Rutherford was even able to discover a new element. He won th Nobel Prize in 1908 and that's where he announced the alpha-helium connection. Kelvin's discoveries inspired military work. The chapter ended with the engineering of bubbles. Bubbles have interested physicists to engage in alternative energy. I wasn't the largest fan of these chapters, the bubble thing was kinda cool I guess. But I can't complain, State Champs 2012!

Lessons 25 and 26

Lesson 25

Lesson 25 basically continued to break down the mole tunnel and mole ratios into 3 steps. The mole tunnel is just the way you set up your equation to solve mole ratio problems. First, convert grams to moles. Next, find the molar ratio, and last convert grams into moles.

 

Practice Problem

 

 

Lesson 26

Lesson 26 talked about limiting reactants. When comparing reactants to find the limiting reactant, compare moles not grams. If you have two products it doesn't matter which one you us, just turn all reactants into the same products. Then we talked about percent yield. The equation for percent yield is the actual amount, divided by the theoretical amount and multiplied by 100. The actual number is the number that you would get in a a perfect scenario. The theoretical number account for what you would probably be true to things like water droplets in the beaker and gas escaping. The percent yield can be in moles or grams.

Practice Problem

 

 

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Lessons 23 and 24

Lesson 23

In this lesson we learned about precipitates, which are solids that are produced in a chemical reaction between two solutions. Sometimes The mixing of two ionic solutions results in the formation of a solid. The degree to which a compound dissolves in water is called it's solubility and precipitation is not limited to solids.

In this chart S means soluble (liquid), N means not soluble (solid)

 

Lesson 24

This lesson was all about molar ratios. A mole ratio is a ratio given by the coefficients in a balanced equation, showing how many units of each substance must combine to make the maximum amount of product. Now when these reactants aren't combined in their perfect mole ratio, one reactant runs out (called the limiting reactant) and one is left over, which is called the excess reactant. When you compare things in a balanced equation you must look at the moles.

Practice Problem

 

 

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Disappearing Spoon-Chapters 13 and 14

Chapter thirteen's theme was money and how elements relate to it. We all know the story of Midas, the greedy king whose touch turned things into gold. Naturally humans wanted to replicate this insane power so some scientists looked into it and assumed that the "touch" was just zinc in the soil. So they loaded a furnace up with ores; melted them, molded them, and let them cool. It hardened into gold. That's when the city of gold stories came into light and then the gold rushes. A man named Hannan found a place where gold was everywhere. Boom. GOld rush, panic and chaos in an attmept to get rich. This only escalated when it was discovered that gold can be formed inside rocks when it's mixed with tellurium. Now any rock anywhere had a chance of containg gold. After another story or two the topic changes to light,electrons and aluminum. Charles Hall ran an electric current from homemade batteries through a liquid and dissolved aluminum, creating an energry source that was fast and simple. This idea made him quite famous and the chapter ending with talks of the different ways to spell aluminum.
Chapter Fourteen talked about colors of elements on the periodic table. Johann Wolfgang von Goethe challenged Isaac Newton's theory of how colors work in poem which made him scientific credibility limited. And as the write he was, he wrote a novel about marriages are like chemical reactions, which was moderately hilarious sounding. It talks about AB + CD —> AD + BC in that if one couple comes in contact with another couple, the couples will split up and become in a relationship with a person from the other relationship. The lesson I got here was to never double date and to assume everyone is a backstabber. When Kenneth Parker tried to get his family business to make pens is really when the asthetics really came into play. Through trial and error the Parker 51 pen came out in 1941. The pen basically dissolved fibers of the paper which means it would dry faster. I found that kinda odd.  The tip was ruthenium instead of gold, which made it way cooler than all other pens as well. I felt like 14 was a little obsessed with their pen idea but It was not my least favorite chapter so I guess that's a bonus. Five chapters left!

Lesson 21 and 22

Today we learned about neutralization, which is when a strong base and a strong acid react and form ionic salt and water. This is usually a double exchange of cations. We also learned that when two compounds have the same volumes and the same molarity they have the same number of moles. When this happens it means there are the same number of moles of Hydrogen and hydroxide so the substance is neutral.

Lesson 22

Titration is the neutralization process between a strong acid and base. When a strong acid is mixed with a weak base there isn't enough OH- ions to neutralize all of the H+ ions so the solution will not be neutral. It will however, be closer to 7 than either starting solution.



Practice Problems
4 is for lesson 21 and number 5 is for lesson 22

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Lesson 20

Today we talked about dilution. When you dilute something you make it either less basic or less acidic. 7 is the neutral number in the pH scale and by diluting a solution you can approach 7 but you can't turn an acid into a base and visa versa by dilution. We also learned that between each number on the pH scale there is a 10 fold. So 6 is 10 times more acidic than 7 and 5 is 100 times more acidic than 7 and so on.

 

Practice Problems

1. How much more basic is 9 than 7?

100 times more basic

 

2. To get a pH of 10 how much would you have to dilute 0.010 M of NaOH?

With 99 mL or water and 1 mL of the NaOH solution

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Disappearing Spoon:Chapters 10-12

Almost forgot this blog, hooray for random memories!
Chapter ten talks about medicine and it's connection to the periodic table. Silver was used to keep milk fresh and sterilize plates. Copper is used in things like doorknobs and railings because it has antiseptic properties. When bacteria touches the copper molecules it goes into to a self cleaning mode basically and eventually ends up killing the virus or bacteria. The element Gadolinium has been used to help kill tumors in processes such as radiation. Scientists have discovered that the best and most effective sperimicide is Vanadium.Granted some of these procedures have harmful side effects but nowadays what medicine doesn't? Kean then goes and talks about handedness or the qualities of proteins. The proteins in humans say that most people should be left handed. This obviously isn't true but it's kind of interesting how body compostition can be wrong. The handedness theory was brought to the table by Louis Pasteur when he was looking into lightbending properties. The next interesting scientist was Gerhard Domagk, who performed experiments on his own daughter! (What?! Why would you put your children in immediate danger?) She had a nasty infection from a needle puncture wound. I guess he was given a hard decision, using his drug and possibly killing her, or not using it and the girl losing her arm and or life. he took this chance and it ended up saving her life! After this miracle the drug prontosil went under inspection. Wat happened was a derivative of it, called sulfonamide. This produces folic acid and is more or less bacterial birth control.
Titianium is the only element that can be used safely and effectively in the body. It fuses to the bone and acts as a bridge between bones if need be. It's commonly used for things like hip replacements in the body. Continuing with the human body trend, iodine is used to fight birth defects. After this discovery the West tried to make it mandatory to put iodine in all salt, but India was not happy. Mahatma Gandhi led a march against iodizing salt but sadly for him it was unsuccessful.Today many Indian people still don' use iodized salt because it's too expensive or they are simply not exposed to it.
Then the topic moved from medicine to politics. Marie Curie was unable to get a proper science education because she was a girl so her dad homeschooled her. I guess the boys academy missed out because she went on to win a Nobel Prize with her husband and another on her own after that. Their studies focused on radioactivity as did their daughter Irene's. Sadly, she died at a relatively young age due to all of her exposure to radiation.

Disappearing Spoon: Chapters 8 and 9

Chapter 8 was about technetium, neptunium, and phosphate while also focusing on competition and mistakes. There have been many large mistakes in the scientific community throughout the ages.  Scientists, Linus Pauling and Emilio Segre have some of the largest mistakes for their time. Kean gives some examples of mistakes, like element 43 being discovered many times but that wasn't really the point of the story so I found it boring. But here are the mistakes and problems caused by Pauling and Segre. A scientist at Berkeley named Ernest Lawrence was working when Segrè was fired. Segrè had been working under  Enrico Fermi, who discovered element 93 by shooting uranium samples with neutrons. Edwin McMillan believed that element 93 would act like technetium, and asked Segrè to help him identify the element and its location on the table. After lots of studying McMillan and Serge found the element to be neptunium and was a cousin of rare earths. That means it branches off of the main periodic table. The other mistake man, Pauling, thought he was the one able to crack the code of DNA. Building from innacurate data of other scientists, Pauling made many wrong assumptions about DNA. Some of the inaccuracies stemed from the fact that he was using dead DNA instead of live DNA, which acts differently. He then wrote a paper about his discoveries, and the paper sound its way to Watson and Crick. These two were flabergasted becuase they had created a similiar model before but realized they were wrong and threw it out before sharing with the rest of the scientific community.

Chapter nine talked about toxins. (Oh look! A connection to our class and unit) Biology is more delicate than chemistry because living organisms count on strong amino acid chains. There is a section of the table that has all of the very toxic substances together. One example is Cadmium. This was dumped into the rivers of Japan purposfully, until it was discovered how harmful this substance is. Cadmium made the farmers weak with a disease that kind of reminded me of osteoporosis. It made the people have very weak bones from moving calcium out of the bone and replaacing it with zinc. But the most deadliest element is Thallium. This element because it unravels the amino acid chains in protein and doesn't bond to anything. Graham Fredrick Young experimented with thallium on his family. For obvious reasons he was sent to a mental hospital. But somehow he managed to poison seven other people.  These elements are related because they are around for a long time. Then it talks about Bismuth which is the heaviest element and emits yellow fumes. It expands when frozen and is commonly used in paints and dyes. Bismuth helped scientists study the structure of radioactive matter. Scientists think because of the half life they estimated at twenty billion billion years, Bismuth will live long enough to be the last element to go extinct. After bismuth is polonium, an element that makes people’s hair fall out. Then is radon, which is colorless and odorless and reacts with nothing. It seems like it would be a bogus, unharmful element then right? Wrong. It displaces air, which then sinks into the lungs and discharges radioactive particles that cause lung cancer. Not so harmless after all. The last part of the chapter talks about a teenage boy from Detroit who made a nuclear reactor in his back yard. In a rage after being informed of her son's arrest for stealing car parts his mother throws everything out of the shed where he was working. All of this was covered in radioactive material. Later after joing the Navy this boy is arrested for stealing smoke alarms. It turns out smoke alarms contain radioactive particles to help find smoke. The boy was trying to enhance his smoke dector in his back yard all those years ago. Personally this book is starting to terrify me about the world we live in. Smoke dectors have radioactive particles,what's next? Food?

Lesson 17-19

Lesson 17

In lesson 17 we learned that an indicator is molecular substance that changes color when it comes into contact with an acid or a base.

Acids and bases are corrosive. When pH is 7 it is neutral or pure water. Below 7 is an acid and above 7 is a base. This is a picture of the pH scale.

These pH solutions are classified by their colors you can observe. Acids and bases change the color of indicators.

.

Practice Problem

3. It means that the substance is neutral. 

Lesson 18

In lesson 18 we learned about cabbage juice and its indicator colors. Cabbage Juice: Pink=acidic, Green=basic, Purple=neutral. Substances that add H+ (just one proton) to a solution are acids. Bases are substances that add OH- to a solution. Substances that don't add H+ or OH- to the solution are neutral.

The definitions of acids and bases has changed over time.

• Arrhenius Definition: An acid is any substance that adds hydrogen ion to solution. A base is any substance that adds hydroxide ion to a solution.
• Brønsted-Lowry Definition- An acid is a proton donor. A base is a proton acceptor.

The products of a reaction is always called a conjugate.

(Red) Base + Acid --> Conjugate Acid + Conjugate Base

(Purple) Acid + Base --> Conjugate Acid + Conjugate Base

Strong acids and strong bases dissociate completely into ions, while weak acids do not.

Practice Problem
1. A base is a substance that adds a OH- ion to a substance and an acid is a substance that adds a H+ ion to a substance. 

Lesson 19

Lesson 19 talked more about the pH scale. The pH scale is a logarithmic scale the describes the concentration of H+ ions. pH is related to H+ by the formula: pH=-log[H+] Water dissociates into H+ and OH- ions. Below is a picture of the pH scale and examples of substances that fit into each pH level.

[H+][OH-]=1.0x10^-14

Practice Problem
3A. 4
3B. 12

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Disappearing Spoon Chapters 5-7

These couple chapters focused on war and how warfare effected the periodic table. The first part focused on nitrogen and the attempts made to capture it. Fritz Haber was the scientist who finally achieve this goal. He was trying to create nitrogen bombs to use in WWI, even though this was illegal in the eyes of  the Hague Convention, but his findings ended up going into fertilizers instead. Eventually Haber's research helped save lives by rescuing those who were starving but he also killed a fair number with his bombs. The next part talked about Colorado! (Hooray a connection to life!) On Bartlett Mountain in Colorado, molybdenum was discovered. This is used to strengthen steel and because it could withstand extreme temperatures in was incredibly valuable to the war effort. In a bidding war over the right to this mountain Otis King won and became insanely wealthy by selling the molybdenum to Germany. That was the most exciting part for me because of the Colorado connection. WWI wasn't the only war where chemical warfare was used though. In the Republic of Congo, war broke out after the discovery of large deposits of  tantalum were discovered. This is a metal used in making cell phones in the 90s. The Congo government was so unstable that tibes fought for the money being made by selling the tantalum to huge cell phone companies. In this war about 5 million people died. Later on in the book it talked about Henry Moseley who managed to discover 4 elements before his early death. He did this by creating an electron gun that could find new elements in other elements essentially. When Moseley died scientists began using more math and calculations to find elements.Next the book moved into the Manhattan Project.  The US was trying to perform nuclear warfare by manipulating plutonium and uranium. Not enough would burn out and too much would cause mayhem. This period of time is also where women were brought in to the science world. The wives of scientists who worked on the Manhattan Project would tire through hours of calculations and ended up as an enormous help. Yay women! Then some other large chemical warfare discoveries were made from Berkley. Both berkelium and californium were discovered there and many experiments on alpha and beta particles took place. The research there was competing with Russia to the point where Joseph Stalin was interested in the research to benefit him and the Soviet Union in WWII but failed. I still am not a large fan of this book but there are some little details that i find interesting.

Lesson 16

Lesson 16
In this lesson we basically used all the knowledge we've gained from throughout the chapter to solve problems. We also did an activity where we had to try and figure out which solutions werer which by weighing them and accounting for the molar mass. The rest of our activity involved doing problems.

Practice Problem
2. There is more solute in the container.
7. The NaBr  would weigh the most because it has more solute than NaOH. The KCl weighs  half as much as the other two because, 500 mL is less than 1 L or 1000 mL.

Lesson 15

Lesson 15
The biggest thing we learned in lesson 15 was that you can use a hydrometer to test the molarity of the substance. I really don't think there was much else so there is a practice problem below!

Practice Problem

 









 

 



Lesson 13 and 14

Lesson 13

A solute is a substance dissolved in a solution. A solvent is the substance in which a solute dissolves. A saturated solution is a solution that contains the max amount of a solute for a given amount of solvent. Molecules move from areas of high concentration to areas of lower concentrations. We also learned about molarity. The equation used to find molarity is pictured below.

 

Practice Problem

 

8. B

 

Lesson 14

In lesson 14 we put our knowledge from the previous lesson into practice. We also learned that concentration does not depend on the density of size of a sample. When dealing with ionic compounds, take all the ions in the equation into account. We also learned that volume is always expressed in liters for the equation.

Practice Problem

 

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Disappearing Spoon-Chapters 3 and 4

Chapter three talks mostly about the formation of the periodic table. Who organized it, the different attempts to organize it and all who were involved. Dmitiri Mendeleev is the man given credit for the periodic table. He was able to draft a table and predict where new element would be when they were eventually discovered. However, Mendeleev couldn't have done it alone. The work of Bunsen and Lecoq de Boisbaudran helped immensly. Boisbaudean brought in the idea of gallium and then rethought his predictions afterbeing corrected by Mendeleev. This chapter also talked about the formation of lanthanides. A teen named Johann Friedrich Böttger convinced a crowd he could turn silver into gold and was promptly arrested for alchemy by the king. The king asked him to turn silver into gold for him however, Johann knew he couldn't because his joke with the crowd was fake but he somehow managed to convince the king to pair him with a porcelain maker. While the pair mined for the rok used to make porcelain they discovered copious amounts of a large, unidentified rock. Later on a geochemist was able to indiviually indentify these rocks, six of them became lanthanides. Chapter 4 was all about the elements in space. The topics included the formation of the earth's crust, information about Jupiter and possible theories about why dinosaurs went extinct. A popular theory is that stars heat hydrogen in their cores and fuse it with other hydrogen atoms, making helium. Then helium fuses with helium. This cycle repeats until iron is formed. Jupiter has been deemed a failed star instead of a planet and so many elements have strange affects there. Father and son Luis and Walter Alvarez began studying a limestone deposit which is dated back to when the dinosaurs are thought to have become extinct. What they learned is that basically when a large meteor hit the earth, very large amounts of iridium-rich dust would have arose. This dust would've blocked out sunlight and kept life from surviving. This chapter also talked about dating the earth but it was incredibly boring.

Lesson 12

In lesson 12 we learned that aspartame is much sweeter than fructose. The smaller the LD50 the more toxic it is. LD50 values are of limited use in determining the long term effects of a substance. Even if you don't reach the actual LD50 there could be very serious long term effects that are not accounted for in the LD50.

Practice Problem

The molar mass of C8H11NO3 s 169g.

 

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Lessons 9-11

Lesson 9

Lesson 9 talks more about moles. A mole is also Avogadro's number. The mass of 1 mole is equal to the molar mass. Then on the periodic table the atomic mass is equal to 1 mole of atoms of the element in grams. You use molar mass to convert between moles of atoms and grams of atoms.

Practice Problems

1. The average mass of atoms of an element is listed on the periodic table.

Lesson 10

Lesson ten was more about converting grams, moles, and molar mass. This is where we really put the knowledge we gained in lesson 9 to practice. The most important thing to remember here is to label your numbers with units and make sure your units cancel out.

Practice Problem

5. A) 10 g calcium, Ca

B) 5 g sodium fluoride, NaF

C) 2 g iron oxide, FeO

Lesson 11

Lesson eleven continues to talk about converting mass and molar mass and moles. There is practice problem pictured below.

 

 

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Lessons 7 and 8

In lesson 7 we learned about lethal doses. A lethal dose is an amount of an ingested substance that kills 50% of a test sample of animals. This is expressed in mg/kg. The lethal dose depends on the amount of a substance and the mass of the organism. The smaller the amount the more toxic it is.

Practice Problems

1. The toxicity of different substances is usually measured by exposing lab animals to the substance in different amounts.

 

Lesson 8

In lesson eight we learned about percent error. We did a lab where we had to try and figure out how many small objects were in a Baggie. Then when we learned the correct method we we taught the equation for percent error. This equation is pictured below.

Practice Problems

5. The marbles will have a greater mass because the mass of a marble is greater than the mass of a plastic bead.

 

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Disappearing Spoon: Intro - Chapter 2

The introduction of this book gives the backround of what made the author curious about elements. When he was young and got sick his mother would use a mercury thermometer to take his temperature. Being tha talkative child he was, the thermometer would often fall from his mouth and shatter, sending mercury everywhere. How mercury acted when loose is what intrigued him about science. Chapter one sets the periodic table up the the U.S. It talks about several different elements and where they would be in relation to a map of the U.S. Easch example has a little backround information as well. When talking about Helium, the author also talks about Plato and his philosphies and how they are similiar to Helium. To help understand the noble gases, Maria Goeppert-Mayer is focused on. She helped to create the ideas behind electron shells that we use today. On top of the backround ifo the book also teaches about the table and how it's set up, isotopes and a little about elcetron configuration. Chapter two talks about carbon, silicon and germanium. Carbon is the basis of life. It creates essential amino acids in carbon chains and produces life. Below carbon is silicon, a cousin of somesorts of carbon. Silicon is very similiar to carbon except that it is a solid at human temperatures instead of a gas. Silicon has the potential to carry life but because of it's phase it never will. Lower in the same column is germanium, an element that was experimented with as a semi conductor. The results were disasterous and germanium's name was scarred from ever having life potential like carbon.

Lesson 6

Today we learned about the different types of chemical reactions. They follow these patterns.
Combination: A+B => AB
Decomposition: AB => A+B
Single Exchange: A + BC => AC + B
Double Exchange: AB + CD => AC + BD

Practice Problems
3A. NaOH (aq)+ HNO3 (aq) => NaOH3 + H2 (l)

Lessons 3-5

Lesson 3
Lesson 3 describes the differences between physical and chemical changes. A physical change is a change in matter in which a substance changes form but not identity. A chemical change is a change in matter that results in the formation of a new substance with new properties. Dissolving is considered a physical change. However, ionic compounds do not dissolve the same way as molecular solids.

Practice Problems
6A. Chemical, the equation has changed
6B. Physical, it is the same compound

Lesson 4
Lesson 4 was about the law of conservation of mass. this law states that mass can not be created or destroyed in a physical or chemical change. The exception to this is when you have a gas product. If the gas is not trapped some mass will be lost because it is impossible to account for all gas mass if it is not contained. Individual atoms are conserved in chemical reactions and physical changes. From start to finish the number of atoms in each element stays the same.

Practice Problem
4. C

Lesson 5
Lesson 5 taught us how to balance  chemical equations. To do this always start with the element that only shows up once on each side of the equation. Also when balancing equations you can only change the coefficient.

Practice Problem
1. Chemical equations need to be balanced because mass cannot be created or deswtroyed during the change.

Unit 4 Lessons 1 and 2

Lesson 1
Unit 4 is about toxins which are things that interact with living organisims and can cause harm. Toxins can enter the body by inhaling them, ingesting them or through the skin. Then we talked about how to interpret a chemical equation. there is an example pictured below.

Practice Problems
1. Reactants are the things that combine to form something in a chemical equation. The thing that it forms is called the product.
3. A toxic substance is something that can enter the body and cause harm.

Lesson 2
Lesson two talks more about chemical equations. Chemical equations allow chemists to track and predict changes in matter.

Practice Problem
3A. A solid and an aqueous solution combine to form an aqueous solution and gas.

Unit 3 Review

Lessons 1-4
In these lessons we learned about weather, proportions, density and temperature scales. By learning terms like cold front, low pressure and jet stream we are now able to more easily understand weather and the things that cause it. We learned about the proportionality constant k, which allows us to use other formulas to find volume, pressure and temperature. Then we learned that density= mass/volume. Next we learned the melting and boiling points of the three most common temperature scales used: Farenheit, celcius and kelvin. A picture below describes this in more depth.

Lessons 5-7
We learned how to covert celcius to kelvin by using the equation K=C+273.  We also talked about how gas particles are in constant random motion. when the temperature increases the gas particles speed up. Then we learned that in Charles's Law, volume is proportional to temperature. When temperature increases volume does as well but density decreases. Next we learned about fronts. When cold air overtakes warm air it is a cold front. When warm air takes over cold air it is a warm front.

Lessons 8-10
Sublimation is the change from a solid to a gas. Next we learned that atmospheric pressure is air pressure that's always present on Earth as a result of air molecules hitting surfaces of objects on earth. At sea level and 25C there is 14.7lb/in2 of air pressure from the air around us. This is 1 atm. Next we talked about Boyle's law. Boyle's Law states that the pressure of a given amount of gas is inversely proportional to its volume if the temperature and amount of gas are not changed.

 

 

 

Lessons 11 and 12

In lesson 11 we learned that stated in Boyle's Law the pressure of a given amount of gas is directly proportional to temperature if the gas volume and amount of gas do not change. Temperature must be Kelvin.  We also learned the differences between rigid and flexible containers. Flexible Container: Changing temp or pressure to make the volume change. Charles' law applies when pressure is the constant. Boyle's law applies when temperature is the constant. Rigid Container: Changing the temperature or pressure. Volume is a constant. Applies to Gay-Lussac's law. Then we learned that gas pressure is the force of gas molecules hitting the walls of its container.

 

 

Lessons 13-16

The combined gas law is written as k=PV/T. Then we learned that clouds form when water vapor condenses and forms water droplets. Must have something to condense on. Clouds form when water vapor condenses and forms water droplets. Next we talked about air pressure, which can be determined by measuing the height of a liquid in a container. And finally we talked about moles.  A mole is a unit used to keep track of very large numbers.

1 mole = 602,200,000,000,000,000,000,000 We also learned about standard temperature and pressure (STP). 1 atm = 273 K and 1 mole = 22.4 L at atm. Equal volumes of gases have equal numbers of gas particles if temperature and pressure are the same.


 

Lessons 17 and 18

The ideal gas law has a constant R which is always equal to .082, the equation is pictured below. The equation can be rearranged to solve for any variables and n represents the number of moles. Then we talked about humidity, the amount of water vapor in the air. Relative humidity is the amount of water vapor in the air compared to the maximum amount of water vapor possible temperature. This is expressed in %.

 

 

 

Lesson 19

This lesson talked about hurricanes which are giant stroms that consist of heavy rains and intense high winds.  They form over areas where warm water evaporates into the air and are measured on a scale of 1-5 from least to most severe. The picture below decribes how storms turn into hurricanes.







 

 Practice Problems:



Lesson 18

Today we learned about humidity. Humidity is the density of water viper in the air at any time. It is dependent on air temperature and air pressure. Condensation proves that there is water in the air. The temperature where water vapor condenses tells how much water vapor is in the air. We also learned about relative humidity. Relative humidity is the amount of water vapor in the air compared to the maximum amount of water vapor possible temperature. This is expressed in %.

 

Practice Problems

Why does condensation prove there is water in the air?

The water in the air hits the cold water in a glass and condenses because of the change in temperature, allowing the water vapor to condense onto something.

 

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Lessons 17 and 19

Lesson 17

In lesson 17 we learned about the ideal gas law. The equation for this law is pictured below. You can also rearrange the equation to solve for any variable. R is the constant in this law and is always equal to 0.082. n is the variable representing the number of moles.

Practice Problems

 

Lesson 19

In lesson 19 we learned about hurricanes. Hurricanes are composed of large winds and heavy rain. They form when warm water evaporates into the atmosphere. The severity of a hurricane is measured on a scale of 1-5, 1 is the lowest and 5 is the most severe. There is a picture below that describes how storms turn into hurricanes.

Practice Problem

1. Hurricanes form over warm oceans and it must be at least 80 degrees Fahrenheit with lots of moisture in the air.

 

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Lessons 15 and 16

Lesson 15
In this lesson we learned about number density and air pressure. Air pressure can be determined by measuring the difference in height of a liquid. We also learned the formula for number density, which is pictured below.

Practice Problems
1. Air is less dense as altitude increases. Both the pressure and temperature is less as atltitude increases.


Lesson 16
In this lesson we learned about moles. A mole is a unit used to keep track of very large numbers.
1 mole= 602,200,000,000,000,000,000,000 We also learned about standard temperature and pressure (STP). 1 atm = 273 K and 1 mole = 22.4 L at atm. Equal volumes of gases have equal numbers of gas particles if temperature and pressure are the same.

Practice Problems
1. Chemists invented the mole in order to keep track of the insanely large number of particles in substances

Lessons 13-14

Lesson 12

Today we learned about the combined gas law. The combined gas law is displayed as

 

Or

 

 

 

 

 

 

 

 

 

 

Use if volume, pressure and temperature all vary


Increase in altitude causes a decrease in temperature and pressure

 

Lesson 13

Clouds form when water vapor condenses and forms water droplets. Must have something to condense on. Clouds form when water vapor condenses and forms water droplets. Must have something to condense on.

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Section 12

Today we learned more about the molecular view of gas pressure. Gas pressure is the result of gas molecules striking the walls of a container.A decrease in volume increases the frequency of collisions. This means that the gas pressure will then increase because of the faster motion of molecules.

Practice Problems
3. When the temperature increases, gas particles get excited and move faster causing it to expand.

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Lesson 11

Gay-Lussac's Law: The pressure of a given amount of gas is directly proportional to temperature if the gas volume and amount of gas do not change. Temperature must be Kelvin.

Flexible Container: Changing temp or pressure to make the volume change. Charles' law applies when pressure is the constant. Boyle's law applies when temperature is the constant.

Rigid Container: Changing the temperature or pressure. Volume is a constant. Applies to Gay-Lussac's law.

Practice Problems
2. A flexible container requires changing the temperature of pressure to make the volume change. When pressure is constant Charles' law applies and when temperature is constant Boyle's law applies. A rigid container only applies to Gay-Lussac's law because volume is the constant because in a rigid container there is now where to gain or lose volume.
3. 720L

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Lessons 8-10

Lesson 8

We learned that sublimation is to change from a solid to a gas and that is the case for dry ice. We did a lab where we placed dry ice into an airtight bag and then measured the density of the bag once the dry ice had sublimed. Fog seen around dry ice is actually tiny water droplets.

Evaporation: Phase change from a liquid to a gas.

%error= experimental value - accepted value/ accepted value *100

Gas molecules are about 1000x more dispersed than those of a solid.

 Practice Problems
1. A solid is more dense than a gas because the molecules of a solid are packed closer together.
3. Sublimation is where a solid changes to a gas and evaporation is when a liquid turns to a gas.

Lesson 9

Pressure: Force applied over a certain area. Force per unit area. Gas pressure is caused by gas molecules striking objects or the walls of a container.

Mixtures of all gases that surround you at all times is called the atmosphere.

Atmospheric pressure: Air pressure that's always present on Earth as a result of air molecules hitting surfaces of objects on earth. At sea level and 25C there is 14.7lb/in2 of air pressure from the air around us. This is 1 atm.

Practice Problems
2. Air pressure is when gas molecules hit other things.



Lesson 10

When volume of a gas decreases the pressure increases.

Inverse proportion: 2 variables are inversely proportional to each other if one variable increases as the other decreases.

PV=k or P=k/V Boyle's Law, the relationship between pressure and volume.

Boyle's Law: The pressure of a given amount of gas is inversely proportional to its volume if the temperature and amount of gas are not changed. The equation is above.

Practice Problems
5. Between gas pressure and temperature it is inversely proportional. The relationship between gas pressure and volume is directly proportional.

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