Chapter 8B Name________________Mr. Bennett Date__________

1. Find the percentage composition for the following compounds:

a. K3PO4 b. PbO2 c. Fe2(SO4)3

d. If you have 50.0 g of each of the compounds above, calculate the grams of oxygen in each.

2. Find the empirical formula if:

a. the compound contains 102.6 g of Ca and 97.4 g of F

b. you have 24.0 % C and 76.0 % F

c. the cpd is 29.1 % Na, 40.5 % S, and 30.4 % O

d. it is 40.7 % C, 54.2 % O, and 5.1 % H

2. What is the molecular formula of a compound:a. that has an empirical formula of CH2 and a mass of 126 g/mol ?

b. that has 82.6 % C and 17.4 % H and a mass of 203.4 amu.

c. Nicotine contains C, H and N. The mole ratio between the elements is 5 : 1 : 7 and the molecular mass is 162 g. Find the molecular formula.

d. 1.996 grams of an oxide contains 0.9062 grams of phosphorus and has a mass of 615 g/mol, what is the molecular formula?

2. Find the formula for the following hydrates and then name them.

a. 0.391 grams of Li2SiF6 and 0.0903 g of H2O

b. The hydrate of CuSO4 is calculated to be 36.1 % water. Find the formula for the hydrate.

3. Find the percent by mass of water in Na2CO3 * 10 H2O