1. What is the mass percent composition of sodium sulfite?
Chapter 3 Practice Quiz
Prove that the average atomic mass of carbon is by using the following measurements:
98.89% C12 and 1.11% C13
What is the mass percent composition of sodium sulfite?
A white powder is found to contain 43.64% phosphorus and 56.36% oxygen by mass. The molar mass of the compound is g/mol. What are the empirical and molecular formulas?
If you mix 10.0 grams of calcium with 10.0 grams of silver phosphate,
(a) What amount of silver will you be able to obtain?
(b) How much of the excess reactant will be left over?
(c) If 5.20 g of silver were produced during the experiment, what is the percent yield?

2. Answers
(.9889 x 12) + (.0111 x 13) = 12.01
Na2SO3  total mass: g/mol
Na: (2 x 22.99)/(126.05) x 100 = 36.48%
S: (32.07)/(126.05) x 100 = 25.44%
O: (3 x 16.00)/(126.05) x 100 = 38.08%
Empirical  P2O5
Molecular P4O10
3Ca + 2Ag3PO4  6Ag + Ca3(PO4)2
(a) 7.73 g (silver phosphate was the L.R.)
(b) 8.56 g leftover
(c) 67.3% yield