STOICHIOMETRY REVIEW ANSWERS. 1. The calculation of quantities in chemical equations is called...

STOICHIOMETRY REVIEW ANSWERS

• 1. The calculation of quantities in chemical equations is called

• Stoichiometry

• 2. The first step in most stoichiometry problems is to convert given quantities to

• Moles

• 3. When two substances react to form products, the reactant which is used up is called the

• Limiting Reagent

• 4. The amount of product that forms when a reaction is carried out in the laboratory is the

• Actual Yield

• 5. The maximum amount of products that could be formed from given amounts of reactants is the

• Theoretical Yield

• 6. When an equation is used to calculate the amount of product that will form during a reaction, then the value obtained is called the

• Theoretical Yield

• 7.

2Al(s) + 3Pb(NO3)2(aq) 2Al(NO3)3(aq) + 3Pb(s) • A.) 2 moles Al + 3 molecules Pb(NO3)2 2 molecules Al(NO3)3 + 3 moles Pb

• F

• B.) 2 grams Al + 3 grams Pb(NO3)2 2 grams Al(NO3)3 + 3 grams Pb

• F

• C.) 2 moles Al + 3 moles Pb(NO3)2 2 moles Al(NO3)3 + 3 moles Pb

• T

• 8. In every chemical reaction ___________ stay the same.• The Mass

• 9. In the reaction 2CO + O2 2CO2, what is the ratio of moles of oxygen used to moles of CO2 produced?

• 1:2

• 10. For C5H12 + 8O2 5CO2 + 6H2O

• ______ moles of reactants chemically change into ______ moles of product.

• 9 moles of reactant to 11 moles of product

11. How many moles of oxygen are required to react completely with

14.8 mol Al when given 4Al + 3O2 2Al2O3?

14.8 mol Al x -----------------4 mol Al

3 mol O2

= 11.1 mol O2

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12. Given the balanced equation 16HCl + 2KMnO4 2KCl + 2MnCl2 + 5Cl2 + 8H2O

if 2.0 mol of KMnO4 reacts, how many moles of H2O are produced?

8.0 mol H2O

13. Based on…16HCl + 2KMnO4 2KCl + 2MnCl2 + 5Cl2 + 8H2O

…how many grams of KCl are produced when 3.0 mol of KmnO4 reacts?

3.0 mol KMnO4 x ----------------2 mol KMnO4

2 mol KClX ---------------------

1 mol KCl

74.5 g KCl= 220 g KCl

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14. If CuO + H2 Cu + H2O, how many moles of H2O are produced

when 240 grams of CuO react?

240 g CuO x ----------------80 g CuO

1 mol CuOX ---------------------

1 mol CuO

1 mol H2O= 3.0 mol H2O---------

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------------------

15. In the reaction Zn + H2SO4 ZnSO4 + H2

how many grams of H2SO4 are required to produce

2.3 gram of H2?

2.3 g H2 x -----------------

2 g H2

1 mol H2

x ------------------- x -------------------

1 mol H2

1 mol H2SO4

1 mol H2SO4

98 g H2SO4

113 g H2SO4

=-----------------

----------------

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-----------

-------

-------

16. LiOH + HBr LiBr + H2OIf you start with 15.0 grams of

lithium hydroxide, how many grams of lithium bromide will be produced?

54.4 g LiBr

17. How many molecules of oxygen are required to react completely with 2.96 X 1023 molecules Al when given 4Al + 3O2 2Al2O3?

2.96 x 1023 molecules Al x -----------------4 molecules Al

3 molecules O2

=

2.22 x 1023 molecules O2

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18. How many molecules of oxygen are produced by the

decomposition of 6.54 g of potassium chlorate (KClO3)?

2KClO3 2KCl + 3O2

6.54 g KClO3 x --------------- x --------------- x ------------------ =122.5 g KClO3

1 mol KClO3

2 mol KClO3

3 mol O2

1 mol O2

6.02 x 1023 molecules O2

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4.82 x 1022 molecules O2

• 19. LiOH + KCl LiCl + KOH

• A) I began this reaction with 20 grams of lithium hydroxide.

What is my theoretical yield of lithium chloride?

Convert 20 grams of LiOH Grams of LiCl

35 g LiCl• B) I actually produced 6 grams of lithium

chloride. What is my percent yield?

Actual_________

Theoretical X 100 = 17%

• 20. C3H8 + 5 O2 3 CO2 + 4 H2O

• A) If I start with 5 grams of C3H8, what is my theoretical yield of water?

Convert 5 grams C3H8 Grams of H2O

8.2 g H2O• B) I made 6.1 g of water. What was my percent

yield?

Actual_________

Theoretical X 100 = 74%

21. Be + 2 HCl BeCl2 + H2

My theoretical yield of beryllium chloride was 10.7 grams. If my

actual yield was 4.5 grams, what was my percent yield?

Actual___Theoretical

= 42%X 100

22. CaSO4 + NaI CaI2 + Na2SO4

If 34.7 g of calcium sulfate and 58.3 g of sodium iodide are placed in a reaction vessel, what will be the

limiting reagent?

NaINote: Refer to Limiting Reagent Notes to see how to work it out.