Chemistry homework

HOMEWORK # 3

CHEM 1405

INSTRUCTOR: SIHI

(Show your work. 5 points per question)

1) . Give the Lewis structure and the molecular geometry of the following:

CO32- PCl3

2) The chemical formula for cocaine is C17H21NO4. Find percent composition of N

by mass.

3) Vanillin, a naturally occurring flavoring contains 63.15% C, 5.30% H, and 31.55% O

by mass. What is the empirical formula of vanillin?

4) How many moles are there in a 500 mg tablet of Vitamin C (C6H8O6)?

5) List five characteristics/properties of the gas phase.

6) A bubble from a deep sea diver in the ocean starts with a volume of 35 mL at a

temperature of 170C and a pressure of 11.5 atm. What is the volume of the

bubble when it reaches the surface where temperature is 220C and pressure is

1 atm?

7) What is the density of ozone gas, O3, at STP?

8) What is the mass of potassium iodide (166.00 g/mol) that yields 0.500 g of lead (II) iodide (461.0 g/mol) precipitate?

__Pb(NO3)2(aq) + __KI(s) → __PbI2(s) + __KNO3(aq)

9) What is the volume of oxygen gas at STP from the decomposition of 10.8 g of mercuric oxide

(216.59 g/mol)?

__HgO(s) → __Hg(l) + __O2(g)

10) Define the following:

a. Charles’ Law

b. Polar Covalent Bond