Viviana's Chemistry 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)
a. because there is a 1:2 ratio for oxygen
b. Zn(s)+Au + (aq) →Zn 2+ (aq) +Ag(s)
b. becuase they is an unequal number of elements
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.
2Al + 6HCI ---> 3H2 + AlCl3
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 M 1M 200 mL
5 M 1,000 mL = 2020 / 5,000 = .404 mL
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)
.502 g CH4 1M CH4 1M CO2 44g CO2
16g CH4 1M CH4 1M CO2
= 1.38
.27 g O2 1M O2 1M CO2 44g CO2
32g O2 1M O2 1M CO2
= .37125
102