Chemistry 11
Test Review - answers
1. Write the formula and determine the molar mass for each of the following chemical compounds:
Name of compound
Chemical Formula
Molar Mass (g/mol)
Barium chloride
BaCl2
208.23
Sulfur trioxide
SO3
80.07
Copper(I) phosphate
Cu3PO4
285.62
2. Determine the number of representative particles/grams in each of the following:
Grams
Representative Particles
23.8 g NaOH
3.26 x 1023 f.u.
3.5 x 1025 molecules of C6H12O6
1.0 x 104 g
13.55 g Cl2
1.151 x 1023 molecules
3. Determine the number of moles found in each of the following substances.
Grams or mL/L
Moles
12.68 g NaCl
0.2170
21.0 L NO2
0.938
56 ml O2
0.0025
25.8 g Fe2O3
5.85
4. How many atoms are in 23.0 g of NaCl? 4.47 x 1023 atoms
5. The percentage composition of Teflon, a substance used for the nonstick surface of cooking utensils, is 24% carbon and 76%
fluorine by mass. What is the empirical formula of Teflon? CF2
6. Analysis of an acid shows it to contain 0.17 g of hydrogen, 2.82 g of sulfur and 5.67 g of oxygen. What is the simplest
formula for this compound? H2 SO4
7. An ore containing zinc, carbon and oxygen and having a mass of 485.35 g is analyzed and found to contain 46.59 g of carbon
and 186.37 g of oxygen. What is the empirical formula of this compound? ZnCO3
8. A compound consisting of aluminum and chlorine has a mass of 17.82 g. The aluminum in the compound has a mass of
3.60g. Find the percentage composition of this compound. Al = 20%, Cl = 80%
9. A compound consisting of carbon, hydrogen, and oxygen has a mass of 40.85g. Analysis that the compound contains 10.90 g
of carbon and 0.90 g of hydrogen. What is the percentage composition of this compound? C = 27%, H = 8%, O = 71%
10. Calculate the mass of metal in 1500 kg of PbO. 1.4 x 106 g of Pb
11. Find the mass of aluminum present in 58.52 g of aluminum oxide. 29.3 g of Al
12. Calculate the amount of hydrogen present in these compounds:
350 g C3H8 63.6 g of H
20.2 g NaHSO4 0.17 g of H