Download Final Exam SG Part 1 (Unit 5).

Chemistry Spring Semester Study Guide Part 1: Mole & Stoichiometry
Mole concept
1. What is Avogadro’s number and what does it represent?
2. S8 + 8O2 →8SO2
a. What is the ratio of reactants to products? ___:___
b. If you double the concentration of O2, how many moles of S8 would be required to
react with all of the oxygen? ____
Molar Mass
1. What is the molar mass of NO2?
2. What is the molar mass of Ca(NO3)2
3. What is the molar mass of sulfur pentafluoride based on the following equation:
5SF5 + 2I2O5 →4IF5 + 5SO2
1-Step Mole Conversions
1. How many moles are there in 24 grams of FeF3?
2. How many moles are there in 3.3 x 1023 molecules of N2I6?
3. How many liters are there in 0.934 moles of LiCl?
4. How many atoms are there in 0.230 moles of NH4OH?
2-Step Mole Conversions
1. How many liters are there in 450 grams of Na2SO4?
2. How many grams are there in 4.5 x 1022 molecules of Ba(NO2)2?
3. How many molecules are there in 12.2 liters of Cu(NO3)2?
4. How many liters are there in 9.4 x 1025 molecules of H2?
Stoichiometry
3-Step Mole Conversions
1. ___ C6H12O6 + ___ O2 __ H2O + __ CO2
a. If 3.20 moles of C6H12O6 react, how many moles of CO2 will be produced?
b. How many moles of O2 are needed to react?
2. ____N2 + ____H2 → ____NH3
a. What volume of hydrogen is necessary to react with 5.04 liters of nitrogen to produce
ammonia (NH3)?
b. How many grams of hydrogen are necessary to react completely with 50.0 g of
nitrogen?
3. Bromine reacts with sodium hypoiodite in a single replacement reaction.
a. Write a chemical equation for this reaction. Make sure it is balanced.
b. How many grams of bromine are needed to completely react with 4.60 X 1023 molecules of
sodium hypoiodite?
4. Sulfur dioxide reacts with hydrogen sulfide to produce sulfur gas and water.
a. Write a chemical equation for this reaction. Make sure it is balanced.
b. How many ATOMS of sulfur dioxide are needed to produce 34.2g of water?
Limiting Reactants (conceptual application)
1. Suppose you are going to make sandwiches that contain specifically 2 slices of bread and 1
slice of ham. If you have a total of 23 slices of ham and 50 slices of bread, how many
sandwiches can you make?
2. Consider the reaction stated below: N2 + 3H2 → 2NH3
a. Suppose you have 4 moles of N2 and 6 moles of H2, which is the limiting reactant?
b. Suppose you have 4 moles of N2 and 6 moles of H2, how much NH3 would be
expected to be produced?
3. Consider the model below to answer the following questions:
a. What molecule (black or white) is the limiting reactant?
b. What is the ratio of black and white molecules to produce the products?
c. How many moles are produced from the moles of the reactants?
d. If you double the amount of white molecules (so now you have 8 pairs) but keep the
same amount of black molecules, how many molecules can you produce?
4. Percent Yield
a. ___Sb4O6 + ____C → ____Sb + ____CO
Determine the percent yield for the reaction between 28.1 g of Sb4O6 and excess C if
17.3 g of Sb is recovered during the lab.
b. ____NH3 + _____O2 → _____NO + _____ H2O
Determine the percent yield for the reaction between 15.8 g of NH3 and excess oxygen
if 21.8 g of NO is produced in the lab.
5. Percent Composition (Percent by mass)
a. Find the percent composition of a compound that is made up of 4.56 g of carbon, 3.23
g of hydrogen, and 0.439g of oxygen.
b. What is the percent composition of Al within Al2(SO4)3
c. How many grams of Al are in 3.2grams of Al2(SO4)3