HW Answers
10.15 & 16
Catalyst

In the following chemical reaction,
hydrogen peroxide is broken down into
water and oxygen.
◦ __H2O2 → __H2O + __O2




Balance the chemical equation.
Is this a decomposition or synthesis
reaction?
What is the mole ratio of water to
oxygen?
What is the mole ratio of hydrogen
peroxide to water?
Objectives and Agenda
Objective: I can create mole ratios from a
balanced equation and make mole to
mole conversions.
 Agenda:

◦ Catalyst
◦ Learning target logs
◦ Mole ratio and conversion practice
Learning Target Logs &
Portfolios
We will be tracking progress towards
standards mastery on learning target logs
for Unit 4.
 Please put your name on the learning
target log.
 We will go through how to fill it out
together.

Assignment

Read p. 302 – 305; Do practice problems
p. 304 #1 & 2, p. 311 #1, 4(a), 6.

For more practice:
◦ Pp. 329-330 # 8, 9, 21, 22
p. 304 #1
Calculate the amounts requested if
1.34 mol H2O2 completely react
according to the following equation.
2H2O2 → 2H2O + O2
a. Moles of Oxygen (O2) formed?
 Converting from mol H2O2 to mol O2

1.34 mol H2O2
This is the amount
given in the question.
1 mol O2___
X 2 mol H O
2 2
This is the mole ratio
from the balanced
equation.
= 0.67 mol O2
p. 304 #1
Calculate the amounts requested if 1.34
mol H2O2 completely react according to
the following equation.
2H2O2 → 2H2O + O2
b. moles of water (H2O) formed?
 Converting from mol H2O2 to mol H2O

1.34 mol H2O2
2 mol H2O
X 2 mol H O
2 2
= 1.34 mol H2O
p. 304 #2
Calculate the amounts requested if
3.30 mol Fe2O3 completely react
according to the following equation.
Fe2O3 + 2 Al→ 2 Fe + Al2O3
a. moles of aluminum (Al) needed?
 Converting from mol Fe2O3 to mol Al

3.30 mol Fe2O3
2 mol Al____ = 6.60 mol Al
X 1 mol Fe O
2 3
p. 304 #2
Calculate the amounts requested if
3.30 mol Fe2O3 completely react
according to the following equation.
Fe2O3 + 2 Al→ 2 Fe + Al2O3
b. moles of iron (Fe) formed?
 Converting from mol Fe2O3 to mol Fe

3.30 mol Fe2O3
2 mol Fe___ = 6.60 mol Fe
X 1 mol Fe O
2 3
p. 304 #2
Calculate the amounts requested if 3.30
mol Fe2O3 completely react according to
the following equation.
Fe2O3 + 2 Al→ 2 Fe + Al2O3
c. moles of aluminum oxide (Al2O3)
formed?
 Converting from mol Fe2O3 to mol Al2O3

3.30 mol Fe2O3
1 mol Al2O3 = 3.30 mol Al2O3
X 1 mol Fe O
2 3
p. 311 #1, 4(a)
1.
4.
The mole ratio is the conversion factor
that is present in almost all
stoichiometry calculations.
(a) How many moles of BrCl form when
2.74 mol Cl2 react with excess Br2?
Br2 + Cl2 → 2BrCl
2.74 mol Cl2
2 mol BrCl
X 1 mol Cl
2
= 5.48 mol BrCl
p. 311 #6
A: In order to solve stoichiometry problems we
have to use moles and not just convert from
mass to mass because the balanced chemical
equation expresses the ratios of reactants and
products according to moles, not grams.