CHEM 111 General Chemistry I
1.
Aluminum sulfate, Al(SO4)3, is used in tanning leather, purifying water, and manufacture of antiperspirants. Calculate its molar mass.
a. 450.06 g/mol b. 342.15 g/mol c. 315.15 g/mol d. 278.02 g/mol e. 74.98 g/mol
2.
Calculate the molar mass of Ca(BO2)26HO.
a. 273.87 g/mol b. 233.79 g/mol c. 183.79 g/mol d. 174.89 g/mol e. 143.71 g/mol
3.
Potassium dichromate, KCrO2, is used in tanning leather, decorating porcelain and water proofing fabrics. Calculate the number of chromium atoms in 78.82 g of K,CrO.
a. 9.490 X 1025 Cr atoms 2.248 X 1024 Cr atoms c. 1.124 X 1024 Cr atoms d. 3.227 X 1023 Cr atoms 1.613 x 1023 Cr atoms
4.
Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain. Calculate the mass in grams of 3.65 102 molecules of SO3.
a. 6.06 104 g b. 2.91 X 102 g C. 4.85 x 102 g d. 20.6 g e. 1650 g
5.
Calculate the mass in grams of 8.35 1022 molecules of CBr4.
a. 0.0217 g b. 0.139 g c. 7.21 g 12.7 g e. 46.0 g
6.
Balance the following equation: BO3(s) + HF(l) BF3(g) + H,O(l)
a. b. c. d. e.
B,O3(s) + 6HF(l) B2O3(s) + H6F6(l) BO;(s) + 2HF(l) B2O3(s) 3HF(l) B2O3(s) + 6HF(l)
2BF3(g) + 3H,O(l) B2F6(g) + HO3(l) 2BF3(g) HO(l) 2BF;(g) + 3HO(l) 2BF3(g) + 6H