CHM166 Chapter 3 - Chemical Reactions and Reaction Stoichiometry

Chemistry

Chapter 3: Chemical Reactions and Reaction Stoichiometry

Homework Assignment

All work and calculations must be shown

Question 1:

Balance the following chemical equations:

a.

b.

c.

d.

Question 2:

Balance the following chemical equations:

a.

b.

c.

d.

Question 3:

Balance the following chemical equations and indicate whether they are combination, decomposition, or combustion reactions:

a.

b.

c.

d.

e.

Question 4:

Using the periodic table calculate the formula weights for each of the following compounds: (Show All Work) All answers should include 4 decimal places.

a. Nitric acid, HNO3

b. Potassium permanganate, KMnO4

c. Calcium phosphate, Ca3(PO4)2

d. Quartz, SiO2

e. Gallium sulfide, Ga2S3

f. Chromium(III) sulfate, Cr2(SO4)3

g. Phosphorus trichloride, PCl3

Question 5:

Calculate the percentage by mass of oxygen in the following compounds:

a. Morphine, C17H19NO3

b. Codeine, C18H21NO3

c. Cocaine, C17H21NO4

d. C66H75N9O24

Question 6:

Calculate the following quantities:

a. Calculate the mass, in grams, of 0.0150 mol of CdS

b. Calculate the number of moles of NH4Cl if you have 86.6g of NH4Cl

c. Calculate the number of molecules in 8.447 X 10-2 moles of C6H6

d. Number of oxygen atoms in 6.25 X 10-3 moles of Al(NO3)3

Question 7:

Calculate the following quantities:

a. Calculate the mass, in grams, of 1.223 moles of iron(III) sulfate

b. Calculate how many moles of NH4+ ions are present in 6.955 g of (NH4)2CO3

c. Calculate the mass, in grams, of 1.50 X 1021 molecules of aspirin, C9H8O4

d. Calculate the molar mass of diazepam (Valium) if 0.05570 mol has a mass of 15.86g

Question 8:

Determine the empirical formulas of the compounds with the following compositions of mass:

a. 55.3% K, 14.6% P, and 30.1% O

b. 24.5% Na, 14.9% Si, and 60.9% F

c. 62.1% C, 5.21% H, 12.1% N, and the remainder is O

Question 9:

What is the molecular formula of each of the following compounds?

a. Empirical formula is CH2, molar mass is = 84.0 g/mol

b. Empirical formula is C2H4O, molar mass = 88.0 g/mol

Question 10:

Refer to the following balanced chemical equation:

The reaction above demonstrates the reaction between potassium superoxide and carbon dioxide to make potassium carbonate and oxygen gas. This is the reaction that takes place in self-contained breathing equipment used by rescue workers.

a. How many moles of oxygen gas are produced when 0.400 moles of KO2 reacts completely?

b. How many grams of KO2 are needed to form 7.50 g of O2?

c. How many grams of CO2 are used when 7.50 g of O2 are produced?

Question 11:

Refer to the following unbalanced chemical equation:

a. Balance this equation

b. Calculate the number of grams of CO that can reaction with 0.350 kg of Fe2O3

c. Calculate the number of grams of Fe and the number of grams of CO2 formed when 0.350 kg of Fe2O3 reacts.

d. Show that your calculations in parts b and c are consistent with the law of conservation of mass.

Question 12:

Refer to the following balanced chemical equation:

a. Which is the limiting reagent when 0.500 moles of H2SO4 and 0.5600 moles of Al(OH)3 are allowed to react?

b. How many moles of Al2(SO4)3 are generated under the conditions described in (a)

c. How many moles of the excess reactant remain after the completion of this reaction?

Question 13:

Refer to the following balanced chemical equation:

If 5.00 g of sulfuric acid and 5.00 g of lead(II) acetate are mixed, calculate the number of grams of sulfuric acid, lead(II) acetate, lead(II) sulfate, and acetic acid present in the mixture after the reaction is complete.