Test 1 Study Guide
Chemistry – Chapter 11
Name:
Solve the following problems showing ALL work:
1. __________What is the % concentration by mass of Sulfur in Aluminum Sulfate, Al2(SO4)3?
2. __________What is the mass of 4.25 x 1023 molecules of CaCO3?
3. __________What is the empirical formula of a compound that contains 40% carbon, 4.70% hydrogen, and
53.3% oxygen by mass?
4. __________What is the percent concentration of Hydrogen in Ammonium Phosphate, (NH4)3PO4?
5. __________How many molecules are found in 329 grams of H2SO4?
6. __________The chemical analysis of aspirin indicates that the molecule is 60% carbon, 4.44% hydrogen, and
35.56% oxygen. Determine the empirical formula for aspirin.
7. __________A compound was found to contain 49.98 g carbon and 10.47 g hydrogen. The molar mass of the
compound is 58.12 g/mol. Determine the molecular mass of the formula.
8. ___________A 10 gram sample of a compound contains 7.22 g of magnesium and 2.78 g of nitrogen. What is
its molecular formula if the molecular mass of the formula is 600 g/mol?
9. __________What is the mass o 4.4 x 1021 molecules of SiO2?
10. __________How many atoms are in 14.6 moles of K?
11. ___________How many atoms are in 155 grams of Cu?
12. __________155 grams of Li2SO4 contains how many formula units?
13. __________What is the mass of 11.2 moles of Aluminum Chloride, AlCl3?
14. __________How many formula units of Potassium Carbonate, K2CO3, are in 760 grams of this compound?
15. __________How many moles are in 45.7 grams of Magnesium Cyanide (MgCN2)?
16. __________How many moles of Calcium Chloride (CaCl2) are in 150 grams?
17. __________How many formula units of Calcium Chloride (CaCl2) are in 150 grams?
18. __________How many grams does 5.5 x 1025 atoms of phosphorus have?
19. __________55.0 grams of Potassium Sulfate (K2SO4) is what number of moles?
20. __________A 100 gram sample of Sodium Carbonate (Na2CO3) hydrate is heated and 37.03 g of anhydrous
Sodium Carbonate remains. What is the formula for the hydrate?
21. __________When 67.9 g of a Calcium Chloride (CaCl2) hydrate is heated, 33.5 g of water is released. Find the
formula for the hydrate.
22. Be able to define mole, molar mass, percent composition, hydrate, anhydrous, Avogadro’s number, empirical
formula, molecular formula. In addition, be able to explain what a crucible is used for and describe what
happened in the Formula of a Compound Lab.