Download Stiochiometric Calculations WS 1:

Name ____________________________________ Date _________ Hr ___
Stiochiometric Calculations WS 1: (30 Pts)
We can get the mole ratio from the chemical equation. Don’t forget to balance the chemical equation
first!!!!! Theoretical stoichiometric calculations are important because they show the maximum amount of
product that could be obtained before a reaction is run in the laboratory. It helps us to make predictions
about chemical reactions without having to run the reaction sin the laboratory. Solve the following
stoichiometric calculations. SHOW ALL WORK!!!!!!
1. The elements lithium and oxygen react explosively to form lithium oxide, Li2O. How
many moles of lithium oxide will form if 2 mol of lithium react? (2pts.)
2. The disinfectant hydrogen peroxide, H2O2, decomposes to form water and oxygen gas.
How many moles of O2 will result from the decomposition of 5 mol of hydrogen
peroxide? (2pts.)
3. When sodium azide is activated in an automobile airbag, nitrogen gas and sodium are
produced according to the equation:
2NaN3(s) 2Na(s) + 3N2(g)
If 0.500 mol of NaN3 react, what mass in grams of nitrogen would result? (2pts.)
4. Carborundum, SiC, is a hard substance made by combining silicon dioxide with coke
(C) as follows: SiO2(s) + 3C(s)  SiC(s) + 2CO(g)
What mass in grams of SiC is formed from the complete reaction of 2.00 mole of carbon?
(2pts.)
5. Zinc metal can be obtained from zinc oxide, ZnO, by reacting the oxide with the
element carbon. The products of the reaction are Zn and CO2. What mass in grams of
zinc oxide is needed to react completely with 5.00 mol of carbon? (2pts.)
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Name ____________________________________ Date _________ Hr ___
6. Coal can be converted to methane gas by a process called coal gasification. The
equation for the reaction is the following:
2C(s) + 2H2O(l)  CH4(g) + CO2(g).
What mass in grams of carbon is required to react with water to form 1.00 mol CH4?
(2pts.)
7. Sulfur dioxide, SO2, is an unwelcome result of burning soft coal in power plants. Some
of the SO2 ends up as sulfuric acid in acid precipitation. The net reaction is as follows:
2SO2(g) + O2(g) + 2H2O(l)  2H2SO4(l).
What mass in grams of SO2 is needed to react with 1200.g of O2? (2pts.)
8. Chlorine gas can be produced commercially by passing an electric current through a
concentrated solution of sodium chloride (brine). The unbalanced equation is as follows:
2NaCl(aq) + 2H2O(l)  2NaOH(aq) + Cl2(g) + H2(g).
a. If the brine contains 250 g of NaCl, how many moles of Cl2 can be produced?
(2pts.)
b. How many moles of H2 gas can be produced? (2pts.)
9. The compound PtCl2(NH3)2 is effective as a treatment for some cancers. It is
synthesized by the reaction shown in the following equation.
K2PtCl4 (aq) + 2NH3(aq) 2KCl(aq) + PtCl2(NH3)2 (aq)
a. How many moles of K2PtCl4 must react in order to produce 30.0 g of
PtCl2(NH3)2? (2pts.)
b. How many moles of NH3 are needed to produce 30.0 g of PtCl2(NH3)2? (2pts.)
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Name ____________________________________ Date _________ Hr ___
10. Sodium peroxide reacts vigorously with water to produce sodium hydroxide and
oxygen. The unbalanced equation is the following:
Na2O2(s) + H2O(l)  NaOH (aq) + O2(g)
a. What mass in grams of O2 is produced when 50.0 grams of Na2O2 react? (2pts.)
b. What mass in grams of water is needed to react completely with the Na2O2?
(2pts.)
11. Milk of magnesia, a suspension of Mg(OH)2 in water, reacts with stomach acid, HCl,
in a neutralization reaction.
Mg(OH)2(s) + 2HCl(aq)  2H2O(l) + MgCl2(aq)
a. What mass in grams of MgCl2 will be produced if 3.00 g of Mg(OH)2 reacts? (2pts.)
b. What mass in grams of HCl is required to completely react with 3.00 g of MgCl2?
(2pts.)
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