3 Step Stoichiometry
Part A Review: For the following chemical equations, write the possible mole ratios.
a. 2 CO + O2 โ 2 CO2
2 CO 2 CO 1 O2
1 O2 2 CO2 2 CO2
b. Al2(CO3)3 โ Al2O3 + 3 CO2
1Al2(CO3)3 1 Al2(CO3)3 1 Al2O3
1 Al2O3 3 CO2 3 CO2
c. 2 CO + O2 โ 2 CO2
2 CO 2 CO 1 O2
1 O2 2 CO2 2 CO2
Part B Review: Using arrows to map your work solve the following 1-step and 2-step stoichiometry
problems.
a. How many moles of CO are needed to react completely with 7 moles of O2?
2CO + O2 โ 2 CO2
7 moles CO x 2 moles O2 = 3.5 moles O2
2 moles CO
b. How many moles of carbon dioxide, CO2, can be formed by the decomposition of 5 moles of
aluminum carbonate, Al2(CO3)3?
Al2(CO3)3 โ Al2O3 + 3 CO2
5 moles Al2(CO3)3 x 3 moles CO2 = 15 moles CO2
1 moles Al2(CO3)3
c. How many grams of carbon monoxide, CO, are needed to react completely with 3 moles of
oxygen gas, O2?
