1. Chemistry 141
Lecture 8
Friday, September 22, 2017

2. Recall from last time that the formula weight of Na3PO4 is 163. 9 amu
Recall from last time that the formula weight of Na3PO4 is amu. What is the percentage by mass of phosphorus in Na3PO4?
44.0.
11.7.
26.7.
18.9.
Answer: d

3. How many formula units are in a 0.2550 g sample of aluminum chloride?

4. A sample contains 5. 28 g of Sn and 3. 37 g of F
A sample contains 5.28 g of Sn and 3.37 g of F. What is the empirical formula of the compound?

5. A sample is analyzed and found to contain 85.7% N and 12.5% H by mass. What is the empirical formula of the compound? The molecular weight of the compound is g/mol. What is its molecular formula?

6. Al(OH)3 is used as an antacid to neutralize stomach acid, HCl
Al(OH)3 is used as an antacid to neutralize stomach acid, HCl. How many grams of HCl can react with g of Al(OH)3?