Name: __________
AP Chemistry Summer Assignment Summer 2016 General Guidelines: The summer assignment must be hand written. The assignment is due on the first day back to school, September 7, 2016. If the entire assignment is not handed in on that day, you will be dropped from AP Chemistry. This is a department policy for all AP Courses that is meant to emphasize the importance of being prepared and working independently.
Format for Summer Assignment: Textbook Portion: Each section of problems should be labeled with the chapter number and page number. (Example: Chapter 2, pg 98) For each problem you are assigned, be sure to include the problem number followed by the hand written answer. All work, formulas, substitutions, conversions, significant figures, units and calculations must be clearly shown. If I have to guess at what your work is showing, I will guess you did it wrong. Use complete sentences and thorough explanations in answering all essay type questions. Critical Thinking Portion: Part A should be a document that is separate from the textbook questions. It may be typed or handwritten. Part B questions should be answered in the spaces provided within the packet.
Textbook: The textbook used for the summer assignment is a free, online text from Rice University. This WILL NOT be the text we will use for class during the year. Directions for accessing this online text are found below. 1. Go to https://openstaxcollege.org/textbooks/chemistry 2. Click on “Get This Book” on the right side of the screen. 3. You are then given the option of seeing a website version of the text or downloading your own PDF copy on to your computer. You can use whichever you like. 4. You may be asked to donate money. Simply click “Continue without donating” If you have technical issues accessing this site, please contact Mr. Johnson or Mrs. Allen via email. Paper copies are also available if you will not have internet access over the summer.
Additional Tips: An AP Chemistry review book is sold in book stores (Barnes and Noble, etc) that we highly recommend. It will help show you the style of questions in the course and will be beneficial in completing the summer assignment. Read each chapter before you complete the assigned questions. We will skim over these topics very quickly and you will be expected to have a solid background knowledge in them. Email us with any serious questions or concerns. We are happy to help wherever we can. Take notes on the chapters you are responsible for working on. Writing things down is a great way to help information sink in and start off the AP Chemistry process.
Have a great summer!!!
Mr. Johnson and Mrs. Allen
Textbook Portion: Read the following chapters and complete each problem as described on the front side of this handout. Chapter
Exercises
Chapter 1
Pg 57(64) #9, 16, 23, 28, 39, 40, 44a-d, 45a-d, 54a-d, 76a-d and 95
Chapter 2
Pg 120(127) #11, 16, 22, 30, 37, 45, 49, 51, 52, 56 and 57
Chapter 3
Pg 166(173) #3, 10, 12, 16a, 22, 24, 26, 33a, 35 and 38
Chapter 4
Pg 219(226) #3, 5, 11, 12, 14, 16 and 19
*** IMPORTANT *** The content within these units will not be taught at any point during the AP Chemistry Course. A Test on these topics will be given on the second day that we are back in school (Thursday, September 8, 2016). These units cover only the very introductory material that you learned in Honors or regular chemistry.
Critical Thinking Portion: Part A - Experimental Design It is extremely important that an AP Chemistry student can use their knowledge and skills to design and implement experiments in the laboratory. Design an experiment to collect data that supports the claim that a 1.0 M NaCl solution is a homogeneous mixture. Describe 1) the steps, 2) the data you would collect, and 3) how the data supports the claim. Laboratory equipment for your experiment should be taken from the list below. (You may not need all of the equipment.) 50-mL beakers Volumetric pipets (5 mL, 10 mL and 25 mL) Balance Hot plate
100 mL of 1.0 M NaCl(aq) Stirring rod Drying oven Fume hood
Part B - Modelling and Data Analysis It is also very important that an AP Chemistry student can examine, analyze, and synthesize information. Often times this information is given in the form of “models” which present the data visually in the form of pictures, diagrams, tables or graphs. Complete the modelling activity on the following pages.
Relative Mass and the Mole How can atoms be counted using a balance?
Why? Consider the following equation for a chemical reaction: 2H2 + O2 → 2H2O This can be interpreted as two molecules of hydrogen and one molecule of oxygen combining to form two water molecules. But how often do chemists limit their reactions to one or two molecules? Usually a reaction is done with an unimaginable number of molecules. How then do chemists know they have the right mix? The molecules need to be quickly counted! How do we count molecules? The answer is the unit called the mole. This activity will start by considering two egg farmers (a chicken farmer and a quail farmer). They produce such large numbers of eggs that they can’t count them all individually, so they count in dozens of eggs in some cases, while in other cases they use mass. Weighing is often easier than counting!
Model 1 – Eggs Chicken Number of eggs Mass of the in the sample sample 1
Quail Number of eggs Mass of the in the sample sample
37.44 g
1
10
10
438
438
1 dozen
1 dozen
1 million
1 million
2.34 g
Ratio of numbers of eggs
Ratio of masses of eggs
1:1
16 : 1
1. Consider the data in Model 1. a. What is the mass of a standard chicken egg? b. What is the mass of a standard quail egg? c. Show mathematically how the 16:1 ratio of masses was calculated in the last column of Model 1. 2. Use a calculator to complete the table in Model 1. Divide the work among group members. Reduce all ratios to the lowest whole numbers possible.
Relative Mass and the Mole
1
3. Imagine you have two baskets—one filled with quail eggs and one filled with the same number of chicken eggs. a. Which basket would be heavier? b. How many times heavier would that basket be? c. Explain mathematically how it is possible for you to answer Question 3b with confidence, even though you don’t know the actual number of eggs. 4. A farmer weighs out 32.0 kg of chicken eggs. a. What mass of quail eggs would he need to weigh out to have the same number of eggs in both samples?
b. If the farmer had weighed out 32.0 pounds of chicken eggs (rather than kilograms), what mass of quail eggs would he need to weigh out to have the same number of eggs in both samples? 5. A farmer makes up a new counting unit called a “cluckster.” a. If the farmer had 3 clucksters of chicken eggs and 3 clucksters of quail eggs, what could you say about the ratio of their masses? b. Does it matter in this problem how many eggs are in a “cluckster”? Explain.
Read This! Let’s take what we learned in the egg model and apply it to atoms. Like eggs, atoms of the same element may have slightly different masses (remember isotopes). The periodic table lists an average atomic mass for the atoms in a sample of each element. These masses are recorded in “atomic mass units” where 1 amu is approximately equal to the mass of a proton (or neutron).
2 POGIL™ Activities for High School Chemistry
Model 2 – Atoms Oxygen Number of Mass of the atoms in the sample sample 1
16.00 amu
Sulfur Number of Mass of the atoms in the sample sample 1
10
10
1 dozen
1 dozen
1 million
1 million
1 mole
16.00 grams
1 mole
Ratio of numbers of atoms
Ratio of masses of atoms
32.00 amu
32.00 grams
Note: The masses shown for oxygen and sulfur have been rounded to make the arithmetic a bit easier.
6. What is the ratio of the mass of an oxygen atom to the mass of a sulfur atom? 7. Fill in the table in Model 2 in a similar fashion to the eggs table in Model 1. Divide the work evenly among group members. Reduce all ratios to the lowest whole numbers possible. 8. Circle the phrase below that completes the sentence.
When two samples contain the same number of atoms _______________________.
the masses of the samples will be equal.
the ratio of the sample masses will be equal to the ratio of the atom’s masses.
the masses are unrelated.
9. Explain why it is not necessary to know how many atoms are in “1 mole” to finish the last row of the table in Model 2. 10. How would the number of oxygen atoms in a 16.00 lbs sample compare to the number of sulfur atoms in a 32.00 lbs sample? 11. In the front of the room, there is a bottle that contains a 32.00 g sample of sulfur. This is 1 mole of sulfur. Estimate how many atoms are in the bottle. Your group must reach consensus.
Read This! A long time ago chemists discovered what you have just discovered: The relative masses of the elements can be used to “count” atoms. If you measure out a sample equal to an atom’s atomic mass in grams, you always end up with the same number of atoms. Chemists call that quantity the mole—a quantity of any sample whose mass is equal to its atomic mass in grams.
Relative Mass and the Mole
3
Model 3 – Molar Mass Average Mass of a Single Particle
Average Mass of One Mole of Particles (Molar Mass)
1 atom of hydrogen (H)
1.01 amu
1 mole of hydrogen atoms (H)
1.01 g
1 atom of copper (Cu)
63.55 amu
1 mole of copper atoms (Cu)
63.55 g
1 molecule of oxygen (O2)
32.01 amu
1 mole of oxygen molecules (O2)
32.01 g
1 molecule of water (H2O)
18.02 amu
1 mole of water molecules (H2O)
18.02 g
1 formula unit of sodium chloride (NaCl)
58.44 amu
1 mole of sodium chloride formula units (NaCl)
58.44 g
12. Look at a periodic table. What number in each element box would a chemist use to find the values in the “Average Mass of a Single Particle” column in Model 3? 13. How is the mass of a single particle changed to get the mass of one mole of particles? 14. Which sample contains more atoms, 18.016 amu of water or 18.016 g of water? Explain. 15. If the formula mass of iron(II) sulfate (FeSO4) is 151.9 amu, what is the molar mass of iron(II) sulfate? 16. Use a periodic table to calculate the molar mass of ammonia (NH3). 17. How would the number of atoms in a 1.01 g sample of hydrogen compare to the number of atoms in a 63.55 g sample of copper?
Read This! So how many “things” are in a mole? By estimating the size of atoms and taking volume measurements of 1 mole samples scientists can estimate that 1 mole = 6.022 → 1023 particles or 602 200 000 000 000 000 000 000 particles (More than you could count in a lifetime!) This number is called Avogadro’s number, named after Amedeo Avogadro.
4 POGIL™ Activities for High School Chemistry
18. Fill in the blanks below using a periodic table. Be sure to include units of g or amu on all masses.
1 atom of helium has a mass of ___________.
1 mole of helium contains __________________ atoms, and has a mass of ___________.
1 formula unit of calcium chloride (CaCl2) has a mass of ___________.
1 mole of CaCl2 contains _________________ formula units, and has a mass of ___________.
Relative Mass and the Mole
5
Extension Questions 19. Use a periodic table to answer the following questions. a. Fluorine gas consists of diatomic molecules of fluorine (F2). How many molecules of fluorine are in one mole of fluorine? b. What is the mass of 1 mole of fluorine gas? c. How many atoms of fluorine are in this sample? Show your work.
20. The mass of one mole of lead (Pb) atoms is 207.2 g. Use a proportion to calculate the number of lead atoms in a 15.00 g sample of lead.
21. What is the mathematical relationship between atomic mass units (amu) and grams (g)?
1 gram = _____________ amu
6 POGIL™ Activities for High School Chemistry
