1. Fingernail- Polish Remover Is Primarily Acetone (C3H6O). How Many Acetone Molecules Are

HW10: Week 10 Problem Set Honors Chemistry Due Date: Friday, October 31st, 2014 Name: ______TP: ______

Directions: Complete each of the following problems on a separate sheet of paper. To be considered complete, you must have every answer completed on a separate sheet of paper, ALL WORK MUST BE SHOWN, and stapled directly to this handout. This problem set is due at the beginning of class on Friday, October 31 st , 2014. Score:

1. Fingernail- polish remover is primarily acetone (C3H6O). How many acetone molecules are in a bottle of acetone with a volume of 325 mL? (density of acetone = 0.788 g/mL) ______/16

2. The rock in a lead ore deposit contains 84% PbS by mass. How many kilograms of the rock must be processed to obtain 1.0 kg of Pb?

3. Complete the table of compounds that contain only chromium and oxygen.

Formula Name Molar Mass % Cr (by mass) % O (by mass) Chromium (III) oxide

84.00 61.90%

100.00 48.00%

4. Samples of several compounds were decomposed, and the masses of their constituent elements were measured. Calculate the empirical formula for each compound. a. 0.104 mol K, 0.052 mol C, and 0.156 mol O b. 5.28 g Sn and 3.37 g F c. 62.1% C, 5.21% H, 12.1% N, and the remainder O

5. A 45.2 mg sample of phosphorus reacts with selenium to form 131.6 mg of the selenide. What is the empirical formula of the phosphorus selenide?

6. Caffeine, a stimulant found in coffee and soda, has the mass percent composition: C, 49.48%; H, 5.19%; N, 28.85%; O, 16.48%. The molar mass of caffeine is 194.19 g/mol. Find the molecular formula of caffeine.

7. Estradiol is a hormone in the human body. Elemental analysis of estradiol gave the mass percent composition: C, 79.37%; H, 8.88%; C,11.75%. The molar mass of estradiol is 272.37 g/mol. Find the molecular formula of estradiol.

8. Seawater contains approximately 3.5% NaCl by mass and has a density of 1.02 g/mL. What volume of seawater

contains 1.0 g of sodium?

Define Your Pride.