Monday, October 22nd
 Continue in Chapter 6
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
1
Mole–Mole Factors from
Chemical Equations
A mole–mole factor is a ratio of the moles (from the
coefficients) for any two substances in an equation.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
2
Guide to Calculating Quantities in
a Chemical Reaction
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
3
Calculating Quantities in a
Chemical Reaction
How many moles of CO2 can be produced when
2.25 moles of C3H8 react according to the following
balanced reaction?
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
4
Mass of Product from Mass of
Reactant, C2H2
Acetylene gas, C2H2, burns in oxygen emitting high
temperatures used for welding metals. How many
grams of CO2 can be produced when 54.6 g of C2H2
are burned?
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
5
Mass of Product from Mass of
Reactant, C2H2
Acetylene gas, C2H2, burns in oxygen emitting high
temperatures used for welding metals. How many
grams of CO2 can be produced when 54.6 g of C2H2
are burned?
Step 1 State the given and needed quantities.
Analyze the Problem.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
6
Mass of Product from Mass of
Reactant, C2H2
Acetylene gas, C2H2, burns in oxygen emitting high
temperatures used for welding metals. How many
grams of CO2 can be produced when 54.6 g of C2H2
are burned?
Step 2 Write a plan to convert the given, to the
needed quantity (moles or grams).
grams molar moles mole-mole moles molar grams
C2H2 mass C2H2 factor
CO2 mass CO2
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
7
Mass of Product from Mass of
Reactant, C2H2
Acetylene gas, C2H2, burns in oxygen emitting high
temperatures used for welding metals. How many
grams of CO2 can be produced when 54.6 g of C2H2 are
burned?
Step 3 Use coefficients to write mole–mole factors;
write molar mass factors if needed.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
8
Mass of Product from Mass of
Reactant, C2H2
How many grams of CO2 can be produced when 54.6 g
of C2H2 are burned?
Step 4 Set up the problem to give the needed
quantity (moles or grams).
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
9
Learning Check
Determine the mass (g) of NH3 that can form from
62.3 grams of N2 according to the following reaction.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
10
Solution
Determine the mass (g) of NH3 that can form from
62.3 grams of N2 according to the following reaction.
Step 1 State the given and needed quantities.
Analyze the Problem.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
11
Solution
Determine the mass (g) of NH3 that can form from
62.3 grams of N2 according to the following reaction.
Step 2 Write a plan to convert the given to the
needed quantity (moles or grams).
factor
grams molar
molar moles mole-mole
moles molar
molar grams
mass
N2 mass
mass
N2 mole-mole
factor
NH3 mass
NH3
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
12
Solution
Determine the mass (g) of NH3 that can form from
62.3 grams of N2 according to the following reaction.
Step 3 Use coefficients to write mole–mole
factors; write molar mass factors if needed.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
13
Solution
Determine the mass (g) of NH3 that can form from
62.3 grams of N2 according to the following reaction.
Step 4 Set up the problem to give the needed
quantity (moles or grams).
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
14
Theoretical, Actual, and Percent
Yield
 Theoretical yield is the maximum amount of
product, which is calculated using the balanced
equation.
 Actual yield is the amount of product obtained when
the reaction takes place.
 Percent yield is the ratio of actual yield to theoretical
yield.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
15
Guide to Calculations for
Percent Yield
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
16
Calculating Percent Yield
On a space shuttle, LiOH is used to absorb exhaled
CO2 from breathing air to form LiHCO3. What is the
percent yield of the reaction if 50.0 g of LiOH gives
72.8 g of LiHCO3?
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
17
Calculating Percent Yield
On a space shuttle, LiOH is used to absorb exhaled CO2
from breathing air to form LiHCO3. What is the percent
yield of the reaction if 50.0 g of LiOH gives 72.8 g of
LiHCO3?
Step 1 State the given and needed quantities.
Analyze the Problem.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
18
Calculating Percent Yield
What is the percent yield of the reaction if 50.0 g of LiOH
gives 72.8 g of LiHCO3?
Step 2 Write a plan to calculate the theoretical
yield and the percent yield.
Calculation of theoretical yield:
grams
LiOH
molar
mass
moles mole-mole
LiOH factor
moles molar
LiHCO3 mass
grams
LiHCO3
Calculation of percent yield:
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
19
Calculating Percent Yield
What is the percent yield of the reaction if 50.0 g of LiOH
gives 72.8 g of LiHCO3?
Step 3 Write the molar mass for the reactant and the
mole–mole factor from the balanced equation.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
20
Calculating Percent Yield
What is the percent yield of the reaction if 50.0 g of LiOH
gives 72.8 g of LiHCO3?
Step 3 Write the molar mass for the reactant and the
mole–mole factor from the balanced equation.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
21
Calculating Percent Yield
What is the percent yield of the reaction if 50.0 g of LiOH
gives 72.8 g of LiHCO3?
Step 4 Solve for the percent yield ratio by dividing the
actual yield (given) by the theoretical yield and
multiplying the result by 100%.
Calculation of theoretical yield:
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
22
Calculating Percent Yield
What is the percent yield of the reaction if 50.0 g of LiOH
gives 72.8 g of LiHCO3?
Step 4 Solve for the percent yield ratio by dividing the
actual yield (given) by the theoretical yield and
multiplying the result by 100%.
Calculation of percent yield:
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
23
Limiting Reactant
A limiting reactant in a chemical reaction is the
substance that is used up first and limits the amount of
product that can form. The other reactant, called the
excess reactant, is left over.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
24
Example: Limiting Reactant
How many peanut butter sandwiches could be made
from 8 slices of bread and 1 jar of peanut butter?
With 8 slices of bread, only 4 sandwiches could be
made. The bread is the limiting item.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
25
Example: Limiting Reactant
How many peanut butter sandwiches could be made
from 8 slices of bread and 1 tablespoon of peanut
butter?
With 1 tablespoon of peanut butter, only 1 sandwich
could be made. The peanut butter is the limiting item.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
26
Calculating Moles of Product from
Limiting Reactant
Calculate the moles of product (CH3OH) that can form
given 3.00 moles of CO reacts with 5.00 moles of H2.
What is the limiting reactant?
a. What mole–mole equalities will be needed in the
. calculation?
b. What are the mole–mole factors from these
. equalities?
c. What is the number of moles of CH3OH from each
. reactant?
d. What is the limiting reactant for the reaction?
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
27
Calculating Moles of Product from
Limiting Reactant
Calculate the moles of product (CH3OH) that can form
given 3.00 moles of CO reacts with 5.00 moles of H2.
What is the limiting reactant?
a. What mole–mole equalities will be needed in the
calculation?
1 mole of CO = 1 mole of CH3OH
2 moles of H2 = 1 mole of CH3OH
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
28
Calculating Moles of Product from
Limiting Reactant
Calculate the moles of product (CH3OH) that can form
given 3.00 moles of CO reacts with 5.00 moles of H2.
What is the limiting reactant?
b. What are the mole–mole factors from these equalities?
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
29
Calculating Moles of Product from
Limiting Reactant
Calculate the moles of product (CH3OH) that can form
given 3.00 moles of CO reacts with 5.00 moles of H2.
What is the limiting reactant?
c. What is the number of moles of CH3OH from each
reactant?
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
30
Calculating Moles of Product from
Limiting Reactant
Calculate the moles of product (CH3OH) that can form
given 3.00 moles of CO reacts with 5.00 moles of H2.
What is the limiting reactant?
d. What is the limiting reactant for the reaction?
The limiting reactant is H2, which produces the smaller
number of moles of product, 2.50 moles of CH3OH.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
31
Calculating Moles of Product from
Limiting Reactant
Calculate the moles of product (CH3OH) that can form
given 3.00 moles of CO reacts with 5.00 moles of H2.
What is the limiting reactant?
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
32
Calculating Mass of Product from
Limiting Reactant
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
33
Calculating Mass of Product from
Limiting Reactant
How many grams of CO can be produced from a
mixture of 70.0 g of SiO2 and 50.0 g of C?
Step 1 State the given and needed quantities.
Analyze the Problem.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
34
Calculating Mass of Product from
Limiting Reactant
How many grams of CO can be produced from a
mixture of 70.0 g of SiO2 and 50.0 g of C?
Step 2 Use coefficients to write mole–mole factors;
write molar mass factors, if needed.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
35
Calculating Mass of Product from
Limiting Reactant
How many grams of CO can be produced from a
mixture of 70.0 g of SiO2 and 50.0 g of C?
Step 2 Use coefficients to write mole–mole factors;
write molar mass factors, if needed.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
36
Calculating Mass of Product from
Limiting Reactant
How many grams of CO can be produced from a
mixture of 70.0 g of SiO2 and 50.0 g of C?
Step 3 Calculate the number of moles of product
from each reactant and determine the limiting
reactant.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
37
Calculating Mass of Product from
Limiting Reactant
How many grams of CO can be produced from a
mixture of 70.0 g of SiO2 and 50.0 g of C?
Step 4 Use the molar mass to convert the smaller
number of moles of product to grams.
1 mole of CO = 28.0 g of CO
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
38
Learning Check
If 48.2 grams of Ca are mixed with 31.0 grams of N2, how many
grams of Ca3N2 can be produced?
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
39
Solution
If 48.2 grams of Ca are mixed with 31.0 grams of N2,
how many grams of Ca3N2 can be produced?
Step 1 State the given and needed quantities.
Analyze the Problem.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
40
Solution
If 48.2 grams of Ca are mixed with 31.0 grams of N2,
how many grams of Ca3N2 can be produced?
Step 2 Use coefficients to write mole–mole factors;
write molar mass factors, if needed.
© 2013 Pearson Education, Inc.
1 mole of Ca
= 40.1 g of Ca
1 mole of N2
=
Chapter 6, Section 6
28.0 g of N2
41
Solution
If 48.2 grams of Ca are mixed with 31.0 grams of N2,
how many grams of Ca3N2 can be produced?
Step 2 Use coefficients to write mole–mole factors;
write molar mass factors, if needed.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
42
Solution
If 48.2 grams of Ca are mixed with 31.0 grams of N2,
how many grams of Ca3N2 can be produced?
Step 3 Calculate the number of moles of product
from each reactant and determine the limiting
reactant.
The limiting reactant is Ca, which produces 0.402 mole Ca3N2.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
43
Solution
If 48.2 grams of Ca are mixed with 31.0 grams of N2,
how many grams of Ca3N2 can be produced?
Step 4 Use the molar mass to convert the smaller
number of moles of product to grams.
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
44
Wednesday, October 24th
Quiz - iClicker Chapter 5 and 6
Finish Chapter 6
© 2013 Pearson Education, Inc.
Chapter 6, Section 6
45