Stoichiometry - Calculations
1) Balance the following equation
[ ] HgO
Name: ____________________

[ ] Hg + [ ] O2
2) The molar mass of HgO =
3) The molar mass of O2 =
4) How many moles of HgO are there in 327.10 grams of HgO?
5) How many moles of O2 can be produced from 1.51 moles of HgO?
6) How many grams of O2 can be produced from 0.755 moles of KCl?
7) How many grams of O2 can be produced from 327.1 grams of HgO during the decomposition reaction of HgO?
8) Balance the following equation
[ ] KClO3  [ ] KClO4 + [ ] KCl
9) The molar mass of KClO3 =
10) The molar mass of KCl =
11) How many moles of KClO3 are there in 220.59 grams of KClO3 ?
12) How many moles of KCl can be produced from 1.80 moles of KClO3?
13) How many grams of KCl can be produced from 0.45 moles of KCl?
14) How many grams of KCl can be produced from 1.80 moles of KClO3 during the decomposition reaction of KClO3?
15) Balance the following equation
[ ] Ca3 (PO4) 2
+
[ ]
H2SO4

[ ] CaSO4 + [ ] Ca(H2PO4) 2
16) The molar mass of CaSO4 =
17) The molar mass of Ca3(PO4)2 =
18) How many moles of Ca3(PO4)2 are there in 59.84 grams of Ca3(PO4)2?
19) How many moles of CaSO4 can be produced from .193 moles of Ca3(PO4)2?
20) How many grams of CaSO4 can be produced from 0.386 moles of CaSO4?
21) Based on the reaction in #15, how many grams of CaSO4 can be produced from 59.84 grams of Ca3(PO4)2?
Step 1 - Write the balanced equation for the chemical reaction (Just like the reactions worksheet)
Step 2 - Calculate the molar mass of all chemical compounds from step 1 (Using the periodic table of elements)
Step 3 - Use Dimensional Analysis:
Convert from grams X to moles of X
Convert from moles of X to moles of Y – (Using Molar Ratios)
Convert from moles of Y to grams of Y
Example)
How many grams of iron (II) chloride can be produced from 17.3 grams of iron (II) oxide?
Step 0 – Need to underline grams of iron (II) chloride = want, and underline 17.3 grams of iron (II) oxide =have
Step 1
_6_ HCl + __1_ Fe2O3  _2_ FeCl2 + _3_ H2O
Step 2 – Calculate molar mass of Fe2O3 = 2(Fe) + 3(O) = 2(55.85g) + 3(16.00g) = 159.70 g/mol of Fe2O3
FeCl2 = 1(Fe) + 2(Cl) = 1(55.85g) + 2(35.45g) = 126.75 g/mol of FeCl2
Step 3 –
Grams X to Moles X
17.3 g Fe2O3 x
1 mol Fe2O3
x
159.70 g Fe2O3
Moles X to Moles Y
2 mol FeCl2
1 mol Fe2O3
Moles Y to Grams Y
x
126.75 g FeCl2
1 mol FeCl2
= 27.46 g FeCl2
Stoichiometry – Practice Problems
Name: ____________________
1) How many grams of lithium sulfate will be formed when 25 grams of sulfuric acid (H 2SO4) react
with an excess of lithium hydroxide in the following reaction?
____ H2SO4 + ____ LiOH ____ Li2SO4 + ____ H2O
2) How many grams of sodium acetate are required to react completely with 30 grams of iron (III)
nitrate in the following reaction?
____ NaC2H3O2 + ____ Fe(NO3)3 ____ NaNO3 + ____ Fe(C2H3O2)3
3) How many grams of fluorine gas will it take to convert 100 grams of C2H4 to C2H4F2 using the
following reaction?
____ C2H4 + ____ F2 ____ C2H4F2
4) Using the following reaction, how many grams of sodium bromide can be formed from 45 grams of
iron (III) bromide and an excess of sodium?
____ Na + ____ FeBr3 ____ NaBr + ____ Fe
Extra Credit – Solve questions 5 and 6 for Extra Credit. – Clearly identify all of your answers
5) - 85.3 grams of aluminum sulfate reacts with 104.3 grams of calcium phosphate.
5a) - Determine the products that will be formed.
5b) - Determine the mass of ALL products that are formed.
5c) - Determine the limiting reactant in the chemical reaction.
HINT: aluminum sulfate + calcium phosphate  ______________________________
6) - 2.35 grams of zinc metal react with 5.24 grams of copper (II) nitrate.
6a) - Determine the products that will be formed.
6b) - Determine the mass of ALL products that are formed.
6c) - Determine the limiting reactant in the chemical reaction.