Download Mass - Mass Relationships

Notes #3
Grams to grams stoichiometry
4- step bridge
MASS-MASS STOICHIOMETRY!!

Example: How many grams of silver
chloride are produced when 17.0 grams of
silver (I) nitrate react with excess sodium
chloride?
Mass - Mass Relationships
 Write
a balanced equation for the reaction.
(Remember to look up the oxidation numbers so
the formulas are correct).
 Start with mass given.
 Calculate the number of moles of the “given”
substance. AgNO3 = 170g/mole(molar mass
conversion factor)
 Use the mole ratio to determine the moles of the
“required” (unknown) substance to moles of the
“given” substance.(Use the balanced equation.)
 Convert
moles “required” to grams(molar mass
conversion factor)
Mass - Mass Relationships
AgNO3 + NaCl  AgCl + NaNO3
given
required
Grams of
Start w/
1 mole of Moles
grams given given
“required” “required”
Grams of
given
17.0 g AgNO3 1 Mole
AgNO3
169.88g
AgNO3
Moles
given
1 mole
“required”
1 mol AgCl
1 mol AgNO3
= grams
produced
143.32 gAgCl
= 14.3 g AgCl
1 mol
AgCl
Problems:
How much silver carbonate is produced
when 14.3 g of silver chloride reacts with
excess sodium carbonate?
 What kind of reaction is this?
Double displacement.
Write the balanced equation.
2 AgCl + Na2CO3 Ag2CO3 + 2NaCl

2AgCl + Na2CO3  Ag2CO3 + 2NaCl
14.3g
1 mol
277 g
Moles
of
Grams
Grams per mole
mol
Given 1 per
AgCl
Ag
CO
Ag
CO
silver
carbonate
mole
of
required
2
3
2
3 substance
AgCl
= 13.9 g
Moles
of 1 mol
2
mol
143g
Ag2CO3
silver
chloride
AgCl Ag2CO3
AgCl
Practice problems
1.
In a spacecraft, the carbon dioxide exhaled by
astronauts can be removed by its reaction with
lithium hydroxide according to the following
equation:
CO2 (g) + 2LiOH
Li2CO3(s) + H2O (l)
How many moles of lithium hydroxide are
required to react with 20 moles of caron
dioxide?