Chapter 3. Stoichiometry of Formulas and Equations

Chapter 3. Stoichiometry of Formulas and Equations

Concepts and Skills to Review Before You Study This Chapter

1. atomic mass (Section 2.5)

1. names and formulas of compounds (Section 2.8)

1. molecular (or formula) mass (Section 2.8)

1. molecular and structural formulas, and ball-and-stick and space-filling models (Section 2 )

• 3.1The Mole
• Defining the Mole

1 amu = 1.66054x10^-24g

Avogadro’s number

• Molar Mass

• Amount-Mass-Number Conversions

• Mass Percent

• 3.2Determining the Formula of an Unknown Compound
• Empirical Formulas
• Molecular Formulas
• Formulas and Structures

• 3.3Writing and Balancing Chemical Equations

• 3.4Calculating Quantities of Reactant and Product
• Molar Ratios from Balanced Equations
• Reaction Sequences
• Limiting Reactants
• Reaction Yields

1. Calculate the molar mass of…

a.P4O10

b.(NH4)3AsO4

c.Carbon monoxide

d.Calcium nitrite

e.Sodium nitride

1. What is the mass of …..

a.2.40mol of P4O10

b.0.76mol of (NH4)3AsO4

c.0.0040500 mol of carbon monoxide

1. How many moles of compounds are in….

a.50.0g of P4O10

b.100g (not 100.g) of carbon monoxide

1. How many molecules of are in….

a.2.40mol of P4O10

b.50.0g of P4O10

1. How many atoms are in…..

a.2.40mol of P4O10

b.50.0g of P4O10

1. How many oxygen atoms are in ….

a.2.40mol of P4O10

b.50.0g of P4O10

1. Calculate the mass percent of …

a.Oxygen in water

b.Oxygen in hydrogen peroxide

1. A compound made up of bromine and fluorine contains 58.37 mass percent bromine. Determine its empirical formula.

1. A compound contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass O.

1. Balance the following equation:

a.B2O3(s) + HF(l)  BF3(g) + H2O(l)

b.UO2(s) + HF(l)  UF4(s) + H2O(l)

c.Complete combustion of C8H18O3(l)

d.Incomplete combustion of C8H18O3(l)

e.Reaction between magnesium and oxygen

f.Reaction between oxygen and fluorine

g.Decomposition of HgO(s)

1. If 0.400 mol of Cl2 reacts with excess SO2, how many moles of Cl2O are formed?

SO2(g) + 2Cl2(g)  SOCl2(g) + Cl2O(g)

1. How many moles of NH3 are needed to react completely with 13.6 mol of F2?

2NH3(g) + 5F2(g)  N2F4(g) + 6HF(g)

1. How many grams of sodium fluoride (used in water fluoridation and manufacture of insecticides) are needed to form 485 g of sulfur tetrafluoride?

3SCl2(l) + 4NaF(s)  SF4(g) + S2Cl2(l) + 4NaCl(s)

1. How many grams of nitrogen are needed to produce 325 grams of ammonia?

N2(g) + 3H2(g)  2NH3(g)

1. KClO3(s)  KCl(s) + O2(g) [unbalanced]

a.How many grams of oxygen are formed when 26.4 g of potassium chlorate is heated?

b.What is the percent yield if 45.0g of Oxygen is actually produced in a reaction?

1. How many grams of gaseous product is formed when 35.88g of HgO(s) is heated?

1. 4Al(s) + 3O2(g)  2Al2O3(s)

a.A mixture of 4.00mol of aluminum and 7.00mol of oxygen is allowed to react. How many moles of aluminum oxide can be formed?

b.From the question above, how much of which reactant is left over?

c.A mixture of 82.49 g of aluminum and 117.65 g of oxygen is allowed to react. What mass of aluminum oxide can be formed?

d.From the question above, how much of which reactant is left over?