_____ pts. out of 100 possible points = % = Name:

Advanced Chemistry: Test #2 (Stoichiometry)

You must show your work with units using dimensional analysis (where appropriate) to get full credit.

1. How many grams of oxygen gas are required to completely react with 47.36 g of butane (C₄H₁₀) ? (10 pts.)

2. How many oxygen atoms are in 24.63 g of zinc nitrite? (10 pts.)

3. How many grams of aluminum will react with 250.0 ml of 3.50M HCl? (10 pts.)

4. What is the molecular formula of a compound that is 84.42% carbon and 15.58% hydrogen and that has a molecular weight between 140 g/mol and 150 g/mol? (15 pts.)

5. 450.0 ml of 0.350 M zinc nitrate is added to 250.0 ml of 0.500 M sodium phosphate. What is the mass of the zinc phosphate precipitate that forms? (15 pts.)

6. If you try to react 75.0 g of sodium and 25.0 g of nitrogen, how many grams of which reactant are left over after the reaction goes to completion? (15 pts.)

7. Some manganese (Mn) is placed in a crucible and then completely reacts with just enough sulphur to form some solid compound.  (There is no leftover manganese or sulphur.)  The mass of the manganese and crucible is 84.17g.  The mass of the compound and crucible is 134.22 g.  The mass of the crucible is 59.67 g.  What is the simplest formula of the compound? (15 pts.)

8. What is the percent composition of aluminum carbonate? (10 pts.)