Avogadros Number And Molar Mass Handout

Avogadro’s Number and Molar Mass Handout Key
1. What is the coefficient for oxygen when the following equation is balanced using the lowest, whole numbered coefficients?
____ C3H8O(g) + ____ O2 (g) ____ CO2 (g) + ____ H2O(g)
a) 3
b) 5
c) 7
d) 9

2. What is the sum of the coefficients when the following equation is balanced using the lowest, whole numbered coefficients?
_____ PH3 (g) + _____ O2 (g) _____ P4O10 (s) + _____ H2O(g)
a) 10
b) 12
c) 19
d) 22

3. What is the sum of the coefficients when the following equation is balanced using the lowest, whole numbered coefficients?
_____ B2O2 (s) + _____ HF(l) _____ BF3(g) + _____ H2O(l)
a) 8
b) 11
c) 15
d) none of these

4. Aluminum metal reacts with iron(II) sulfide to form aluminum sulfide and iron metal.What is the coefficient for aluminum when the equation is balanced using the lowest, whole-numbered coefficients?
a) 1
b) 2
c) 3
d) 4

5. Calcium phosphate reacts with sulfuric acid to form calcium sulfate and phosphoricacid. What is the coefficient for sulfuric acid when the equation is balanced usingthe lowest, whole-numbered coefficients?
a) 1
b) 2
c) 3
d) none of these

6. What is the molar mass of calcium permanganate?
a) 159 g/mol
b) 199 g/mol
c) 216 g/mol
d) 278 g/mol

7. What is the molar mass of aspartic acid, C4O4H7N?
a) 43 g/mol
b) 70 g/mol
c) 133 g/mol
d) 197 g/mol

8. How many grams does a single chlorine molecule, Cl2, weigh?
a) 5.887 x 10 g
b) 1.177 x 10 g
c) 35.45 g
d) 70.90 g

9. How many grams are there in 0.500 mol of dichlorodifluoromethane, CF2 Cl2 ?
a) 4.14 x 10 g
b) 60.5 g
c) 121 g
d) 242 g

10. How many moles are there in 1.50 g of ethanol, CH3CH2OH?
a) 0.0145 mol
b) 0.0326 mol
c) 30.7 mol
d) 69.0 mol

11. How many molecules are there in 5.00 g of FeSO4?
a) 5.46 x 10 molecules
b) 1.98 x 10 molecules
c) 1.83 x 10 molecules
d) 4.58 x 10 molecules

12. How many grams does 8.50 x 10 molecules of NH3 represent?
a) 0.00830 g
b) 0.417 g
c) 2.40 g
d) 120 g
13. How many oxygen atoms are there in