Final Notebook

Stoichiometry and balanced equations make it possible to use one piece of information to calculate
another. There are countless ways stoichiometry can be used in chemistry and everyday life. Try and
see if you can use what you learned to solve the following problems.
Problem 1
Why are the following equations not considered balanced?
a. H2O(l)→H2(g)+O2(g) There isn't the same amount of oxygen on both sides. The balanced equation is 2H 2 O(l)→2H 2 (g)+O 2 (g)
b. Zn(s)+Au + (aq) →Zn 2+ (aq) +Ag(s)
There isn't Au and Ag on both sides
Problem 2
Hydrochloric acid reacts with a solid chunk of aluminum to produce hydrogen gas and aluminum ions.
Write the balanced chemical equation for this reaction.
6HCL+2Al=3H 2 +2AlCl 3
H1 6
Cl1 6
Al1 2
H2 6
Cl3 6
Al1 2
Problem 3
Given a 10.1M stock solution, how many mL must be added to water to produce 200 mL of 5M
solution?
10.1(1/1000)(5/1)(1/10.1)(1000/1)=5ml
Problem 4
If 0.502g of methane gas react with 0.27g of oxygen to produce carbon dioxide and water, what is the
limiting reagent and how many moles of water are produced? The unbalanced equation is provided
below.
CH4(g)+O2(g)→CO2(g)+H2O(l)
1CH 4 +2O 2 -->1CO 2 +2H 2 O
C1
H4
O2 4
C1
H2 4
O3 4
.502gCH 4
1 mol
2 molH 2 O
16gCH 4 1molCH 4
18gH 2 O
1molH 2 O
0.27g O 2 1 mol 2molH 2 O 18gH 2 O
32gO 2 2molO 2 1molH 2 O
=1.13g H2 O
=0.15g H 2 0
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