Exam #2 Review (Chapter 3 and 4)

1.Which contains the greatest mass of oxygen: 0.75 mol of ethanol (C₂H₅OH), 0.60 mol of formic acid (HCO₂H), or 1.0 mol of water (H₂O)?

• C2H5OH

• HCO2H

• H2O

• None

2. The approximate minimum daily dietary requirement of the amino acid leucine, C₆H₁₃NO₂, is 1.1 g. What is this requirement in moles?

• 1.1 mol C6H13NO2

• 0.0168 mol C6H13NO2

• 131.174 mol C6H13NO2

• 0.0084 mol C6H13NO2

3.The Cullinan diamond was the largest natural diamond ever found (January 25, 1905). It weighed 3104 carats (1 carat = 200 mg). How many carbon atoms were present in the stone?

• 3.738 * 10^29 atoms C

• 1 atom C

• 3.113 * 10^25 atoms C

• 6.022 * 10^23 atoms C

4. Determine the percent ammonia, NH₃, in Co(NH₃)₆Cl₃, to three significant figures.

• 88.9%

• 38.2%

• 6.07%

• 28.1%

5.A compound of carbon and hydrogen contains 92.3% C and has a molar mass of 78.1 g/mol. What is its molecular formula?

• C6H6

• CH

• C3H7

• C6H

6.A major textile dye manufacturer developed a new yellow dye. The dye has a percent composition of 75.95% C, 17.72% N, and 6.33% H by mass with a molar mass of about 240 g/mol. Determine the molecular formula of the dye.

• CHN

• C15H15N3

• C5H5N

• C30H30N6

7.Determine the molarity of 20.54 g of Al(NO₃)₃ in 1575 mL of solution

• 22.02480 M

• 1.22460 M

• 0.06123 M

• 0.61230 M

8.Determine the molarity of 0.005653 mol of Br₂ in 10.00 mL of solution

• 0.5653 M

• 1.1316 M

• 10 M

• 56.53 M

9.What mass of a 4.00% NaOH solution by mass contains 15.0 g of NaOH?

• 62.5 g NaOH solution

• 3.75 g NaOH solution

• 18.75 g NaOH solution

• 375 g NaOH solution

10.Balance the following equations:

PCl5(s)+H2O(l)⟶POCl3(l)+HCl(aq)

• 1, 1, 1, 2

• 3, 5, 7, 9

• 2, 2, 2, 2

• 1, 1, 1, 1