Name Period.

Chem RG Chapter Packet 9 – Stochiometry

Assign Section # Name 10 5

1. Assignment Sheet printed

2. Notes 9.1

3. Notes 9.2

4. 9.1 Ch09 Worksheet #1 (2 pages)

5. 9.2 Ch09 Worksheet #2 (1 page)

6. Quik Lab Quik Lab (turn in separately for graded pts) pts pts

7. 9.2CR Concept Review Ch09 worksheet 3 (3 pages)

Ch 09 Test Review (turn in separately for graded points) pts pts

Fall Sem FE Test Review (turn in separately for graded pts) pts pts

(Total Points = 5 x 10 = 50)

Notes:

1. Your lab report is turned in by itself and receives a separate grade. 2. Your test reviews are graded separately. 3. Website: http://chem-rg-flipped.santiago.groupfusion.net/

EVIDENCE (after you take notes.) You should have at least 4 types of evidence for each set of notes. 1. Number new concepts 1,2,3…/A,B,C… 2. Delete/Cross out unimportant information Unimportant

3. Circle vocab/key terms

4. Identify points of confusion ?

5. Underline/Highlight main Ideas Main Ideas 6. Identify information to be used on a test, essay… *

7. Fill in gaps of information. Reword or paraphrase. ^ 8. Create visuals/symbols of important

information Visuals/symbols

Key Terms

Name Period.

CHEM. RG Ch09 LAB: MASS & MOLE RELATIONSHIPS IN A CHEMICAL REACTION

What to turn in: Objectives Data Table 1 Data Table 2 Calculations # 1-4 Questions # 1-7

Objectives

• To relate masses and moles of reactants and products in a chemical reaction • To predict mole ratios and compare experimental vs. theoretical results.

Background Information

It is useful to be able to predict the yield of product as well as the amount of reactant needed in a chemical reaction. Chemical equations provide both qualitative (verbal) and quantitative (numerical) information.

In this lab you will be reacting solid sodium bicarbonate (sodium hydrogen carbonate) with acetic acid to form carbon dioxide, water, and sodium acetate. The solid product will be dried and massed. The experimental determination of the masses involved will allow you to calculate numbers of moles. The results can be tested against the balanced equation.

NaHCO3(s) + CH3COOH(aq) → CO2(g) + H2O(l) + NaCH3COO(aq)

Materials sodium bicarbonate (baking soda) stirring rod acetic acid (vinegar) hot plate (or burner with tubing) funnel graduated cylinder 50 mL spatula or scoopula forceps crucible tongs

Procedure

1) Measure the mass of a clean, dry evaporating dish. Use as many decimal places as shown—at least to 0.1 g. Record in Data Table 2.

2) Zero (tare) the balance. 3) Add 2.0 to 3.0 grams of sodium bicarbonate to the evaporating dish. Any amount in

between in acceptable. Record the exact mass in Data Table 2. 4) Using your graduated cylinder, obtain 30 mL of acetic acid. 5) Slowly add the 30 mL of acetic acid to the sodium bicarbonate in the evaporating

dish. Stir. If necessary, add a few more drops of acid until the bubbling stops. Caution: Acetic acid can be caustic and corrosive. Do not breathe vapors. Flush all spills with water. 6) Place the evaporating dish on the hotplate on medium high heat (or on a ring clamp with

wire gauze clamped to a ring stand, with burner and tubing). 7) Heat uncovered until the liquid is mostly evaporated.

Caution: Handle hot glassware with forceps and tongs. 8) Keep adjusting the hot plate temperature to maintain a good "boil," but do not

boil too vigorously or the solution may spatter. 9) Heat the contents until only a dry solid remains. 10) Remove the evaporating dish from the heat, and cool it for at least 5 minutes. 11) Mass the cool evaporating dish and solid product. Record mass in Data Table 2. 12) Clean the glassware.

Calculations - SHOW ALL CALCULATIONS on a "Calculations" page! 1) mass moles of sodium bicarbonate (Use bar = bar) 2) mass moles of sodium acetate (Use bar = bar) 3) experimental mole ratio of sodium bicarbonate to sodium acetate (Ans. in #1 divided by ans. in #2) 4) percent yield

DATA TABLE 1

solid reactant liquid reactant solid product liquid product gaseous product

(see directions on how to do this in Question #7 below)

NAME FORMULA

Balanced chemical equation

Theoretical mole ratio (coefficients) of sodium bicarbonate : sodium acetate :

DATA TABLE 2

PRE-REACTION: a. Mass of evaporating dish (this is the empty dish. Subtract this from full dish) g

b. Mass of evaporating dish + sodium bicarbonate _______g c. Mass of sodium bicarbonate used (full dish minus empty dish, "b" - "a") g d. Moles of sodium bicarbonate used (calculation #1) moles

POST-REACTION: d. Mass of evaporating dish and sodium acetate g e. Mass of sodium acetate produced ("d" - "a") g f. Moles of sodium acetate produced (use "e" and calc. #2 to get) moles Experimental mole ratio of sodium bicarbonate : sodium acetate :

Questions 1) Why should acid be added to the solid reactant “until all bubbling stops”? 2) a) How do coefficients differ from subscripts?

b) Give an example of each. 3) How are you sure this reaction involved a chemical change? 4) Give the chemical formula of the product that was lost to the air. 5) Give the chemical formula of the reactant that can harm the skin and lungs. 6) Compare the Theoretical mole ratio of sodium bicarbonate: sodium acetate in

Data Table 1 with the Experimental mole ratio. How close are they to each other? 7) Calculate the percent yield for your reaction as follows:

a. Use Calculation #2 result (above) and mole ratio of sodium acetate to sodium bicarbonate to calculate the theoretical moles for sodium acetate.

b. Use "bar = bar" to convert theoretical moles for sodium acetate into theoretical grams of sodium acetate.

c. Divide your ACTUAL grams of sodium acetate (POST-Reaction MASS (not moles) of of sodium acetate produced BY the THEORETICAL grams you just calculated in "7 b"

d. Multiply your answer in "7 c" by 100 to get the percent yield.

Percent Yield = %

CALCULATIONS: Show all calculations, clearly labeled, on a "Calculations" page

Holt Chapter 9 Stoichiometry

Section 9-1 Introduction to Stoichiometry • Define stoichiometry. • Describe the importance of the mole ratio in stoichiometric calculations. • Write a mole ratio relating two substances in a chemical reaction. • Solve stoichiometry problems between two substances involving mass or number of particles

Proportional Relationships Stoichiometry - __________ relationships between substances in a chemical reaction

Based on the mole ratio - indicated by __________ in a __________ equation Mole ratio - conversion ratio of the amounts __________ of any two substances in a chemical reaction. Molar mass - mass, in grams, of one mole of a substance. Writing Mole Ratios 4 Fe + 3 O2 2 Fe2O3 Fe and O2 4 mole Fe and 3 mole O2

3 mole O2 4 mole Fe Fe and Fe2O3 4 mole Fe and 2 mole Fe2O3

2 mole Fe2O3 4 mole Fe O2 and Fe2O3 3 mole O2 and 2 mole Fe2O3

2 mole Fe2O3 3 mole O2 Using Mole Ratios in Calculations

2 Al2O3(l) 4 Al(s) + 3 O2(g)

If we had 13.0 mol of Al2O3, how many moles of Al can we produce? Use the picket fence 13.0 mol Al2O3 x 4 mol Al = 26.0 mol Al 2 mol Al2O3 How many grams of Al can we produce? (Use “bar = bar) 26.0 mol Al x 26.98 g Al = 701 g Al 1 mol Al

Stoichiometry Steps 1. Write a balanced equation. 2. Identify known & unknown. 3. Line up conversion factors.

Mole ratio - moles ↔ moles Molar mass - moles ↔ grams # of particles - moles ↔ Avogadro

4 Li(s) + O2(g) 2 Li2O(s) How many moles of lithium oxide will form by reacting 2 moles of lithium? WRITE YOUR WORK BELOW

5

done

3

partial

1 printed

Your Turn – SHOW YOUR WORK IN THE SPACE BELOW 2C2H2 + 5O2 → 4CO2 + 2H2O If 3.84 moles of C2H2 are burned, how many moles of O2 are needed?

Bar = Bar Remember “gmma” (gramma) “grams moles molec/atoms” g ⇔ mol ⇔ molec or atoms going “to” goes on “top” going “from” goes on “bottom” Always show the units Data x bar = bar Data x _____ = _____ Learning Check 1. Number of atoms in 0.500 mole of Al: SHOW YOUR WORK BELOW 2.Number of moles of S in 1.8 x 1024 S atoms: SHOW WORK BELOW 3. How many g of lithium oxide formed by reacting 2 moles of lithium? 4Li + O2 2Li2O” SHOW WORK 4. 250. g NaCl, makes how many moles of Cl2? 2NaCl(aq) + 2H2O(l) → 2NaOH(aq) + Cl2(g) + H2(g)

Calculating Mass of A Substance

_________ the equation first! Convert _________ amount to _________ (bar = bar)

Use _____ _____ to find moles of _________ amount. Convert end moles to _________ units (bar = bar) (Spider diagram does this for you.)

Key __1__ mol __PT__ g __AN__ atoms/molec

Milk of magnesia (Mg(OH)2) neutralizes stomach acid (HCl) by the following reaction: Mg(OH)2(s) + 2 HCl(aq) → 2 H2O(l) + MgCl2(aq) What is the mass in grams of magnesium chloride produced from 3.00 grams of Mg(OH)2 (M for MgCl2= 96.21 g/mol and M for Mg(OH)2 = 58.32 g/mol). TRY TO GET AN ANSWER OF 4.90 g. The reaction between H2 and O2 produces 13.1 g of water. How many grams of O2 reacted? ANSWER 11.6 g

Points to Remember 1. Read an equation in _______

2. Convert _______amount to moles

3. Use mole _______to give desired moles

4. Convert moles to _______

Examples:

If 10.1 g of Fe are added to a solution of Copper (II) Sulfate, how much solid copper would form? Fe + CuSO4 → Fe2(SO4)3 + Cu (unbalanced). REMEMBER TO BALANCE. Answer 17.3 g Cu 2Fe + 3CuSO4 Fe2(SO4)3 + 3Cu. Here is another way to find mole ratios: We’d started with 10.1 g Fe & used bar = bar to get 0.181 mol Fe & we need moles of Cu (to then get g of Cu) . Do mole ratio as a cross-multiply problem 2Fe + 3CuSO4 Fe2(SO4)3 + 3Cu 0.181 x Solve for x: 2 • x = 3 • 0.181 x = 3/2 • 0.181 = 0.272 mol Cu Then use bar - bar to get 17.3 g Cu SiCl4 + 2Mg → 2MgCl2 + Si How many grams of Mg are needed to make 9.3 g of Si? Ans. 16.1 g Mg SiCl4 + 2Mg → 2MgCl2 + Si How many g of SiCl4 (M = 169.90 g/mol) to make 9.3 g of Si? Ans. 56.26 g SiCl4 The U. S. Space Shuttle boosters use 3 Al(s) + 3 NH4ClO4 → Al2O3 + AlCl3 + 3 NO + 6H2O How many g Al must be used to react with 652 g of NH4ClO4 (M = 117.5 g/mol)? Ans. 150. g Al. How much water is produced? Ans. 200. g H2O. How much AlCl3 (M = 133.5 g/mol)? 247 g AlCl3

More Practice Problems - Go to worksheet.

9.2 Limiting Reactants & Percentage Yield

• Identify the limiting reactant for a reaction and use it to calculate theoretical yield. • Perform calculations involving percentage yield.

If the amounts of two reactants are given, the reactant __________determines the amount of product formed.

1. Write a __________equation.

2. For __________reactant, calculate the amount of __________formed.

3. __________answer indicates: __________reactant AND amount of __________

Do two stoichiometry problems. The one that makes the __________product is the __________reagent. Your Turn II - 5 minutes. SHOW YOUR WORK BELOW If 10.3 g of aluminum are reacted with 51.7 g of CuSO4 (M = 159.55 g/mol) how much copper is produced?. . . 2Al + 3CuSO4 → Al2(SO4)3 + 3Cu Molar mass CuSO4 = 160 g/mol Molar mass Cu =63.5 g/mol

Percent Yield Actual yield is the amount of product __________ __________from an experiment

Theoretical (possible) yield is the maximum amount of product that __________be produced from the reactant.

Percent Yield is the actual yield __________to the maximum (theoretical yield) possible.

Percent Yield = Actual Yield (g) recovered X 100% Theoretical Yield (g) 45.8 g of K2CO3 react with excess HCl, 46.3 g KCl. Calculate theoretical & % yields of KCl. WORK: Theoretical Yield – do stoich to get answer of 49.4 g. Percent Yield – use formula above to get 93.7% 6.78 g of copper is recovered when 3.92 g of Al are reacted with excess copper (II) sulfate. 2Al + 3 CuSO4 → Al2(SO4)3 + 3Cu What is the actual yield? (read question). Ans. Is __________ What is the theoretical yield? (do stoich) to get 13.85 g What is the percent yield? (use formula) AY = 6.78 g; TY = 13.85 g (Al is LR). Ans. Is 49.0% 2ZnS + 3O2 → 2ZnO + 2SO2 If the typical yield is 86.78%, how much SO2 should be expected to be recovered if 4897 g of ZnS are used with an excess of O2? First, calculate theoretical yield of SO2 (stoich) = (4897)(1/97.46)(2/2)(64.07/1) = 3219 g SO2 Solve for actual yield as follows . . . Since %Y = AY/TY, AY = %Y x TY So, 3219 g SO2 x 86.78% = 2794 g SO2 is what you recover.

Details Percent yield tells us how “efficient” a reaction is. Percent yield cannot be bigger than 100%. How do you get good at this?

Ch09 Worksheet #1: Mole to Mole Stoichiometric Calculations Note: Most “answers” that are provided only show a range to help you see if you are getting close. You still need to find the exact answer.

1. A chemist describes a particular experiment in this way: "0.0400 mol of H2O2

decomposes into 0.0400 mol of H2O and 0.0200 mol of O2." Express the chemistry of this reaction by a conventional equation. Be sure to balance!

2. Octane in gasoline burns as so: 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

a. How many moles of O2 react fully with 4 moles of octane? Ans. Range 25-50 moles

b. How many moles of CO2 can form from 1 mole of octane? Ans. Range 0 – 25 moles

c. How many moles of water are made by with 6 moles of octane? Range 30-60 moles

3. The alcohol in "gasohol" burns as so: C2H5OH + 3 O2 2CO2 + 3 H2O

a. Burning 25 moles of ethyl alcohol need how much oxygen? Ans. Range 60-95 moles

b. If 30 moles of oxygen are consumed, how many moles of alcohol are used up?

c. In one test, 23 moles of carbon dioxide were produced by this reaction. How many moles of oxygen were consumed?

4. Iron ore, Fe2O3, changes into metallic iron when heated together with hydrogen.

Fe2O3 + 3 H2 → 2 Fe + 3 H2O

(a) How many moles of iron are made from 25 moles of Fe2O3?

(b) How many moles of hydrogen are needed to make 30 moles of Fe?

5. Given: H2O + NaCl + NH3 + CO2 → NH4Cl + NaHCO3

How many moles of sodium bicarbonate could be made from 100 moles of NaCl?

6. How many moles of iron, Fe, can be made with 18 moles of carbon monoxide, CO?

Fe2O3 + 3 CO → 2 Fe + 3 CO2

7. How many moles of H2O are produced when 6 moles of O2 is consumed?

2 CH3OH + 3 O2 → 2 CO2 + 4 H2O

8. Solutions of iron(III) chloride, FeCl3, are used in photoengraving and to make ink.

2 Fe + 3 Cl2 → 2 FeCl3

(a) How many moles of FeCl3 form from 24 moles of Cl2?

(b) How many moles of Fe are needed to combine with 24 moles of Cl2

9. How many moles of nitric acid, HNO3, react with 2.56 moles of Cu? Ans. 6.83 moles

3 Cu + 8 HNO3 → 3 Cu(NO3)2 + 2 NO + H2O

10. How many moles of carbon dioxide are produced by burning 1.50 moles of C2H5OH? Hint: write the reaction for complete combustion. Be sure to balance. Ans. 3 moles

Ch09 Worksheet #2 - Stoichiometry

1. Given 2 C4H10 + 13 O2 → 8 CO2 + 10 H2O, show what the following molar ratios should be.

a. C4H10 / O2 b. O2 / CO2 c. O2 / H2O d. C4H10 / CO2 e. C4H10 / H2O

2. Given 2 KClO3 → 2 KCl + 3 O2 How many moles O2 produced from 12.00 moles of KClO3? Range 10-20

3. Given 2 K + Cl2 → 2 KCl How many grams KCl produced from 2.50 g K & excess Cl2. Ans. 4.8 g

4. Given Na2O + H2O → 2 NaOH How many g of NaOH produced from 1.20 x 102 g of Na2O? Ans 154.8 g

5. Given 8 Fe + S8 → 8 FeS What mass of iron is needed to react with 16.0 grams of sulfur? Ans. 27.9 g

6. Given 2 NaClO3 → 2 NaCl + 3 O2 12.00 moles of NaClO3 produces how many g of O2? Ans. 576 g

7. Given Cu + 2 AgNO3 → Cu(NO3)2 + 2 Ag, if 89.5 g Ag produced, how many g of Cu reacted? Ans 26.3 g

8. Molten iron & carbon monoxide are produced in a blast furnace by reacting iron(III) oxide & carbon. Using 25.0 g of pure Fe2O3, how many g of iron can be produced? Fe2O3 + 3 C → 2 Fe + 3 CO Ans. 17.5 g

9. The average human requires 120.0 grams of glucose (C6H12O6) per day. How many grams of CO2 are required for this amount of glucose? The photosynthetic reaction is:

6 CO2 + 6 H2O → C6H12O6 + 6 O2 Ans. 175.9 g

10. Given the reaction: 4 NH3 (g) + 5 O2 (g) → 4 NO (g) + 6 H2O (l)

When 1.20 mole of ammonia reacts, the total number of moles of products formed is:

a. 1.20 b. 1.50 c. 1.80 d. 3.00 e. 12.0 Ans. d

QuikLab Calculations and Write-up Show all work

1a. Show ALL calculations below your answer columns. For each ingredient calculate the maximum number of cookies you could make if you used all of that ingredient, but also had enough of the other ingredients. (HINT: you know that 1 egg could make 24 cookies. How many cookies could you make with 1 dozen eggs IF you had enough other ingredients? Then do the same type of calculation with each other ingredient). Ingredient # cookies could make Ingredient # cookies could make 1 dozen eggs __________________ 3 cups chocolate chips __________________

24 tsp vanilla __________________ 5 lb (11 cups) sugar __________________

1 lb (82 tsp) salt __________________ 2 lb (4 cups) brown sugar __________________

1 lb (84 tsp) baking soda __________________ 1 lb (4 sticks) margarine __________________

1b. Which ingredient above would make the fewest number of cookies? __________________

1c. What is the maximum number of cookies that could be made from the above amount of ingredients? (HINT: you can only make cookies IF you have all the ingredients. So, once you’ve run out of an ingredient, even if you have the other ingredients you cannot make any more cookies) __________________ SHOW ALL CALCULATIONS BELOW:

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Chemistry 6 Stoichiometry

Section: Limiting Reactants and Percentage YieldComplete each statement below by choosing a term from the following list. Terms may be used more than once.

excess product limiting stoichiometric

percentage actual theoretical

1. A(n) reactant is not completely used up in a chemi-cal reaction.

2. A(n) reactant is used up first and thus controls the

quantity of that can be formed in a chemicalreaction.

3. The reactant that runs out first is the reactant.

4. The limiting reactant should be used in calcula-tions to determine the maximum amount of product expected.

5. Cost is a factor in selecting the reactant.

6. In industry, the least expensive reactant is usually used as the

reactant. In this way, the more expensive reactantis completely used up, while some of the cheaper reactant is left over.

7. The yield is a way to describe reaction efficiency.

8. The percentage yield describes how close the yield

is to the yield.

9. The yield must be measured experimentally.

10. The percentage yield figures can be used to predict what the

yield will likely be.

Answer the following items in the space provided.

11. When 3.00 g of Mg is ignited in 2.20 g of pure oxygen, what is the limitingreactant? What is the theoretical yield of MgO? ans. you do LR; yield = 4.96 g

2Mg(s) � O2(g) £ 2MgO(s)

Name Class Date

Concept Review Ch09 Worksheet 3 Skills Worksheet

10 done 5 part

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Chemistry 7 Stoichiometry

Name Class Date

Concept Review continued

12. When 32 g of O2 reacts with 23 g of C2H5OH, what is the limiting reactant?What is the theoretical yield in grams of CO2? Ans. 29 g.

C2H5OH(l) � 3O2(g) £ 2CO2(g) � 3H2O(l)

13. What is the limiting reactant when 154 g of Ag reacts with 189 g of HNO3?What is the theoretical yield in grams of AgNO3? Ans. 243 g.

3Ag(s) � 4HNO3(aq) £ 3AgNO3(aq) � NO(g) � 2H2O(l)

14. A student used 1.34 g of silver to produce silver nitrate. The actual yield was2.01 g. Calculate the percentage yield. Ans. 95.3%.

3Ag(s) � 4HNO3(aq) £ 3AgNO3(aq) � NO(g) � 2H2O(l)

15. To prepare the paint pigment chrome yellow, PbCrO4, a student started with5.552 g of Pb(NO3)2. The actual yield of PbCrO4 was 5.096 g. Calculate thetheoretical yield and the percentage yield. Ans. TY = 5.418 g; PY = 94.06%

Pb(NO3)2(aq) � Na2CrO4(aq) £ PbCrO4(s) � 2NaNO3(aq)

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Chemistry 8 Stoichiometry

Name Class Date

Concept Review continued

16. Determine the actual yield in grams of MgO when 20.0 g of magnesium isburned in air. The percentage yield of the reaction is 97.9%. Ans. 32.5 g

2Mg(s) � O2(g) £ 2MgO(s)

17. Determine the actual yield of Fe2O3 when 10.0 g of iron(II) sulfide is burnedin air. The percentage yield of the reaction is 88.1%. Ans. 8.00 g.

4FeS(s) � 7O2(g) £ 2Fe2O3(s) � 4SO2(g)

18. Determine the actual yield in grams of CCl4 if 175.0 g of Cl2 reacts withmethane. The percentage yield of the reaction is 75.4%. Ans. 71.6 g.

CH4(g) � 4Cl2(g) £ CCl4(g) � 4HCl(g)

Ch9  Test  Review  –  Graded  for  points     Name:__________________________________  Period:____    Use  this  equation  to  answer  the  following  questions:    1N2  +  3H2  →    2NH3          

Write  the  following  Mole  Ratios:  

  N2  /  H2       NH3  /  N2       H2  /  NH3           NH3    /  H2  

 

How  many  moles  of  NH3  will  be  produced  from  5.6  moles  of  H2?     _____________________  

 

 

How  many  mol  of  N2  would  be  required  to  produce  345  g  of  NH3?     _____________________  

 

 

What  mass  of  NH3  is  produced  from  9.8  g  of  H2?         _____________________  

 

 

How  many  atoms  of  N2  are  required  to  produce  0.00234  g  of  NH3?     _____________________  

 

 

What  mass  of  H2  is  needed  to  react  with  23.76  mol  of  N2?       _____________________  

 

 

What  volume  of  hydrogen  gas  is  needed  to  produce  20.0  mol  of  NH3?   _____________________     (Assume  these  densities:      N2:  1.2506  g/L,      H2:  0.0899  g/L,      NH3:  0.771  g/L.    1

st  find  answer  in  grams,  then  use  D  =  m/V  to  isolate  the  variable  “V”  and  then  solve  for  volume.  

1

Chem RG Dr. Lachman Fall Final Exam Review – do 12 questions each day starting 1 week before the exam 1. List the 5 ways you can tell a chemical change has occurred.

a.

b.

c.

d.

e.

2. Tell whether the following is an element (E), compound (C), homogeneous mixture (HO) or heterogeneous

mixture (HE). If the mixture is homogeneous and in water also put “SOL” for solution next to it.

a. Pure carbon dioxide b. granite countertops c. Pure metallic copper

d. Pure salt e. sodium nitrate in water f. sand in water

g. oxygen gas (O2) h. sugar in water

3. In the following, tell whether the change is physical (“P”) or chemical (“C)

a. chopped up wood. _____ b. burning coal _____ c. making wine _____

d. boiling water _____ e. bread getting moldy _____ f. Rusting or tarnishing _____

g. Any bodily function _____ Questions 4 & 5. Use these terms to fill in the blanks. Some may be used more than once. Isotope, fill, different, definite, indefinite, protons, shell, same, ion, neutrons, electrons, charge, isotope, most, least.

4. If an element’s number of ________ changes, then the element has completely changed into another element. If

the element’s mass changes (nucleus size), then it is still the ______ element but the number of _________s are

different. We call this other “version” of the same element an _____________. An _____ is when the protons &

neutrons are the same but the ___________s are different and there is a positive or negative __________. Atoms

ionize to _____ their outer electron __________.

5. Uranium-238 has the same number of ________ as uranium-235, but three more _________. 6. List the 5 steps of the Scientific Method a.

b.

c.

d.

e.

Periodic Table & Trends 7. The PT columns are called __________ & the rows are called __________. 8. Use these terms to name the element types in the following groups. Transition metals, noble gases, alkali

metals, halogens, alkaline earth metals.

a. Group 1 _______________

b. Group 2 _______________

c. Groups 3-12 _______________

d. Group 17 _______________

e. Group 18 _______________

2

For questions 9-13 go to your skeleton notes for chapter 4. At the end of them are two boxes that summarize periodic trends. Copy them into the spaces below. Then MEMORIZE THEM! Use them to answer questions 9-11. Knowing these boxes will be helpful for your final exam. 9. Put in order from LEAST to MOST electronegative (bigger e- hogs): Ba, O, Fe, F, Zn. _______________

10. Put in order from SMALLEST atomic radius to LARGEST: He, Fr, Al, Ir, Ca. _______________

11. Put in order from SMALLEST ionization energy (energy needed to pull an e- off) to LARGEST:

Na, Ar, Cl, Al, Mg. _______________

12. Put in order from MOST reactive to LEAST: Li, Fr, Na, K. _______________

13. Put in order from LEAST reactive to MOST: F, I, Br, Cl. _______________ FINAL EXAM HINTS: When you take the final exam be sure to use the periodic table that comes with the test. Any time you are not sure how to answer a question, look at your periodic table! Also, draw the above two “trends” boxes from memory before answering periodic trends questions. 14. Mendeleev arranged the PT by the properties of the elements. We arrange by _________ __________. Types of Calculations & Balancing Equations 15. Convert the following. (gramsmolesmolecules) Be sure to use 6.022 x 1023 when converting moles into molecules & vice versa. Use bar = bar. You may use your calculator for these questions to help you study. Remember, molecules is NOT the same as moles. See if you can get the same answer as shown below. a. 42 g of NaCl into molecules. Answer: 4.33 × 1023 molecules b. 2.53 x 1024 molecules of Al2(SO4)3 into grams. Answer: 1437 grams c. 5 mol Cl2 into grams. Answer: 354 grams. 16. Give the % composition of each element in the following molecules. Hint. Find the molar masses of each element, divide by the total molar mass, then multiply by 100 to get a percent. ESTIMATE. DO NOT USE A CALCULATOR FOR THESE. YOU WILL NOT BE ABLE TO USE A CALCULATOR ON THE EXAM.

a. CH4 (methane) b. KBr

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17. Balance and Name the type (single replacement, double replacement, decomposition, synthesis, combustion). a. ____CH4 +____ O2 ____H2O + ____CO2 _________________________________ type b. ____Al + ____ HCl ____AlCl3 + ____ H2 _________________________________ c. ____N2 + ____H2 ____NH3 _________________________________ d. ____HCl ____ H2 + ____Cl2 _________________________________ e. ____AgNO3 + ____K ____ KNO3 + ____Ag _________________________________ f. ____AgNO3 + ____BaSO4 ____ Ba(NO3)2 + ____Ag2SO4 ________________________________ 18. The density of a cube is 1.20 g/cm3. Its mass is 4.8 g. What is the volume? (Do without calculator) Chemical Bonding 19. Identify whether a covalent (nonmetal to nonmetal) or ionic (metal to nonmetal) bond. a. CO2 ________ b. NaCl ________ c. NH3 ________ d. MgO ________ 20. As the difference in electronegativity increases (that is, the two elements are further apart on the periodic

table), the bond is more ___________. As is decreases (closer together), the bond is more __________.

21. Draw the Lewis Dot structures for: (Hint: use (happy – have)/2 to find number of bonds) a. CBr4 c. NH3 d. H2O e. C2H4 Ne

22. Write the ionic formulas and the compound’s name (do both!) Be sure to use ionic charges to help you! Hint: use your Rainbow Matrix Help Sheet in the “Helps” section of our website (but you still need to memorize!). During the test remember to use the Periodic Table. a. sodium & chlorine b. beryllium & oxygen c. potassium & sulfur d. aluminum & oxygen e. calcium & iodine f. magnesium & bromine

g. potassium & sulfate h. calcium & hydroxide i. aluminum & carbonate j. ammonium & nitrate k. ammonium & sulfate l. sodium & phosphate 23. In a double replacement reaction potassium bromide reacts with sodium nitrate. The products will be (write names and formulas for the products)

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24. Name the compound Cu(NO3)2. Do it Roman Numeral Style since copper is a Transition Metal! The Roman Numeral indicates the charge vs. how many. 25. Name the following COVALENT molecules. Use prefixes. Remember: 2 nonmetals together OR a nonmetal with a hydrogen is covalently bonded! a. CO2 b. SO3 c. ICl3 d. CCl4 e. PBr5 f. H2O g. P2O5

Stoichiometry Practice: Use a calculator for these. Remember: g mol or mol g use bar = bar. Use mole ratio for going from moles of “A” to moles of “B.” Steps: convert g of “A” to mol of “A” using bar = bar. Use mole ratio to convert mol “A” to mol “B.” Then use bar = bar to convert mol “B” to mol of “A.” 26. Convert 25 moles of Fe2O3 to moles of iron: Fe2O3 + 3 H2 → 2 Fe + 3 H2O. Answer: 50 moles. 27. How many moles of iron can be made with 18 moles of carbon monoxide? Fe2O3 + 3 CO → 2 Fe + 3 CO2 Answer: 12 moles.

28. Given 2 K + Cl2 → 2 KCl How many grams KCl produced from 2.50 g K & excess Cl2. Ans. 4.8 g

29. Given 2 NaClO3 → 2 NaCl + 3 O2 12.00 moles of NaClO3 produces how many g of O2? Ans. 576 g

30. To prepare PbCrO4, a student started with 5.552 g of Pb(NO3)2. The actual yield was 5.096 g. Calculate the theoretical yield (do stoich) and the percent yield (actual ÷ theoretical) x 100. Ans. TY = 5.148 g; PY = 94.1%. Pb(NO3)2 + Na2CrO4 PbCrO4 + 2NaNO3 31. Convert the following to Kelvin or Celsius (use 273; remember, Kelvin is always the larger number)

a. 100 oC b. -50 ºC c. 315 K d. 75 K

32. Absolute zero = ________ K & is where ____ molecular movement stops. 33. Tell if energy is absorbed or released (endothermic or exothermic)….

a. gas to liquid energy _____________ e___________________

b. liquid to solid energy _____________ e___________________

c. liquid to gas energy _____________ e___________________

34. Heat energy gets t_________________d from areas of h______ to c_______ temperature.

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35. Use the terms “increases” and “decreases”: As kinetic energy increases, particle movement ____________

& temp. _______. As kinetic energy decreases, particle movement ______________ & temp. ________.

36 Given the below bond types, put the bond type next to the criteria. a. ionic bonds b. polar covalent bonds c. nonpolar covalent d. metallic bonds

• Electrons are completely transferred. ________________

• Electrons are shared equally between atoms. ________________

• Electrons move freely from atom to atom in an electron “sea”. ________________

• Tend to be solids at room temperature. ________________

• Tend to bend (malleable) or be ductile (bend into wires). ________________

• Electrons are not shared equally between atoms. ________________

• Tend to be gases at room temperature. ________________

• Tend to be liquids at room temperature. ________________

• Formula units are arranged in a crystal lattice. ________________

37. Tell which of the following atoms is larger/smaller than its ion. Hint: did its ion gain or lose electrons? a. N vs. N3- b. Al vs. Al3+ c. Cl vs. Cl- d. K vs. K+ Test Prep Questions—DO WITHOUT A CALCULATOR!!!!!! PRACTICE ESTIMATING. YOU CANNOT USE A CALCULATOR ON THE TEST! YOU MAY USE A PERIODIC TABLE 38. Which of the below could be the combustion of propanol? (CH3CH2CH2OH)

a. 2CH3CH2 CH2OH + 9O2 6CO2 + 8H2O b. CH3CH2 CH2OH + 3O2 2CO2 + 3H2O c. CH3CH2 CH2OH + O2 2CO2 + 3HO d. CH3CH2 CH2OH + 2O2 3CO2 + 2H2O

39. How many moles of carbon-12 are in 6 g? (reminder: no calculators for all these, pick closest answer) a. 0.5 mole b. 2 moles c. 3.01 x 1023 moles d. 6.02 x 1023 moles 40. How many atoms in 97.6 g of Pt (Use bar = bar & PT, but estimate since you cannot use a calculator). a. 5.16 x 1030 b. 3.01 x 1023 c. 1.20 x 1024 d. 1.10 x 1028 41. Given: CH4 + 2O2 CO2 + 2H2O. If one mole of methane 2 moles of oxygen, then…. a. 6.022 x 1023 molecules of CO2 & 6.022 x 1023 molecules of H2O are produced. b. 1.2 x 1024 molecules of CO2 & 1.2 x 1024 molecules of H2O are produced. c. 6.022 x 1023 molecules of CO2 & 1.2 x 1024 molecules of H2O are produced.

d. 1.2 x 1024 molecules of CO2 & 6.022 x 1023 molecules of H2O are produced.

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42. How many moles of methane (CH4) are contained in 96 grams? (Remember, no calculators for all these) a. 3 moles b. 6 moles c. 12 moles d. 16 moles 43. How many atoms in 24.5 g of technetium? (Are you using a calculator??? Don’t! But use Periodic Table) a. 1.5 x 1023 b. 3.3 x 1023 c. 1.9 x 1026 d. 2.4 x 1024 44. How many moles of nitrogen gas are in 9.02 x 1023 molecules? (Moles are not the same as molecules) a. 1.5 b. 2.0 c. 6.02 d. 9.03 45. If 54 g of water are mixed with excess magnesium nitride, how many grams of ammonia are produced? Mg3N2 (s) + 6H2O (l) 2NH3 (aq) + 3Mg(OH)2 (s) a. 1.00 b. 17.0 c. 51.0 d. 153 46. In order to become a theory, a hypothesis should be….

a. obviously accepted by most people. b. a fully functioning experiment c. in alignment with past theories d. repeatedly confirmed by experimentation

47. Matter is made of atoms that have positive centers (neutrons/protons) surrounded by a cloud of negatively charged electrons. This statement is a(n)….

a. theory b. hypothesis c. inference d. observation 48. Which shows an increase in atomic number but a decrease in atomic mass? (Use Periodic Table)

a. Ag to Pd b. Co to Ni c. Ge to Sn d. Cr to Mo 49. Why is cobalt before nickel on the Periodic Table even though it has a higher atomic mass?

a. Nickel has one more proton. b. Cobalt was discovered 1st. c. Nickel has fewer electrons. d. Cobalt has a lower density.

50. How do atomic masses change throughout the Periodic Table? a. Increases from left to right & top to bottom b. Increases from left to right & bottom to top. c. Increases from right to left & top to bottom d. Increases from right to left & bottom to top. 51. Fluorine has chemical properties most like…. (Hint: what is the name of the group fluorine is in?)

a. Manganese b. Tellurium c. Chlorine d. Xenon

52. Which of the following has 6 valence electrons? a. Mg b. Si c. S d. Kr 53. Which best describes the nucleus?

a. Occupies most of the atom’s volume but contains little of its mass. b. Occupies little of the atom’s volume & contains little of its mass. c. Occupies most of the atom’s volume & contains most of its mass. d. Occupies very little of the atom’s volume & contains most of its mass.

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54. Glycine (NH2CH2COOH), glucose C6H12O6, and ethanoic acid (CH3COOH) are found in the human body. The bonds these biological molecule form are…. (Hint: are there metals in these compounds?) a. nuclear b. ionic c. metallic d. covalent 55. H2, Cl2, CO2, C2H8, HCl, H2O (stuff in your body) all have ____________ bonds. (Same hint as above) a. covalent b. ionic c. metallic d. polar 56. Salt crystals like LiCl, hold together well. The reason is due to the cations being so strongly attracted to… a. nearby cations b. protons in the next nucleus c. free electrons moving in the crystal d. nearby anions 57. Which has the same Lewis Dot structure as Oxygen? (Hint: which is in the same group as O2? Use PT) a. Selenium b. Arsenic c. Germanium d. Fluorine 58. The random molecular motion of a substance’s particles is greatest when the substance is a… a. solid b. liquid c. gas 59. Which of these processes is exothermic? (Hint: which does NOT need to absorb energy to happen?) a. water evaporating b. ice melting c. photosynthesis d. water freezing 60. At constant temperature & pressure, liquids differ from gases because the molecules of the liquid… a. have no regular shape/arrangement b. are in constant motion c. have stronger forces of attraction between them. d. take the shape of the container they are in. 61. State whether protons, neutrons or electrons determine an atom’s chemical properties __________.

62. Temperature measures __________ kinetic __________ of a substance’s particles. (See page 43 of text)

63. If there is a metal bonded to a nonmetal in a compound then it must be a/an ________ bond.

64. Identify which compound is covalent (shares electrons) and which is ionic (transfers electrons). Hint: Use your answer in question 63 to help you answer this question.

a. SrCl __________ b. FeCl3 __________ c. PCl3 __________ d. SO2 __________

65. What forms a chemical bond between atoms - mutual attraction of protons, electrons or neutrons? (Circle)

66. How many valence electrons in following? (Hint: Use the “1+, 2+, 3+, skip” chant and the periodic table.

a. alkali metals ____ b. alkaline earth metals _____ c. halogens _____ d. noble gases?_____ 67. Which type of attraction produces the highest boiling point? a. ion-ion b. molecule-ion c. London dispersion forces d. hydrogen bonding 68. Which of the above types of forces in question 67 gives water its high boiling point? _________________

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Draw a blank Periodic Table below with correct number of groups and periods (skip the lanthanides and actinides). Number the groups and the periods. Use to answer #73-76: Hint: Yes, you could just look at a period table, but drawing a blank one yourself will actually help you remember locations, etc. 69. What is the group and period number for the most reactive metal? The most reactive non-metal?

Metal: Gp# _____ Period # _____ Non-metal: Gp # _____ Period # _____

70. What group number has 3 valence electrons? __________

72. Name a group and period number where a metalloid might be (don’t peek, use your blank table above)

73. Who described electrons as being in orbitals? __________; as impossible to know where __________?

74. Circle which of the following is an actinide? (Hint: Use your printed PT) Bi Eu Th Fe

75. Circle which of the following is a lanthanide? Bi Eu Th Fe