Homework Due July 15

pg. 180 #1-12

1. No matter is created nor destroyed.

2. Law of conservation of matter. 

3. Using things up means that materials are chemically changed, but not destroyed so the term throwing away is misleading because no materials are destroyed, they are only changed. 

4. A. Sn-1
         H-1
         F-1
         Sn-1
         H-2
         F-2
Not balanced.
     B. Si-1
          O-2
          C-1
          Si-1
          O-1
          C-2
Not balanced.
     C. Al-1
          O-3
          H-6
          Cl-3
          Al-1
          O-3
          H-6
          Cl-3
Balanced.

5. A. 3
    B. 2
    C. 1

6. A. 1WO3 + 3H2 --> 1W + 3H2O
W-1
O-3
H-6
W-1
H-6
O-3
   B. 2PbS + 3O2 --> 2PbO + 2SO2
Pb-2
S-2
O-6
Pb-2
S-2
O-6
   C. 4Fe + 3O2 --> 2Fe2O3
Fe-4
O-6
Fe-4
O-6

7. A. 1Ca3(PO4)2) + 3H2SO4 --> 2H3PO4 + 3CaSO4
Ca-3
P-2
O-20
H-6
S-3
Ca-3
P-2
O-20
H-6
S-3
   B. 2C8H18 +10O2 --> 16CO2 + 18H2O
C-16
H-36
O-20
C-16
H-16
O-20

8. A. Atom Inventory:
Na-2
S-1
O-4
K-2
Cl-1
Na-2
S-1
O-4
K-2
Cl-1
Yes they are conserved.
     B. The equation is correct, but instead of using coefficients, the student used subscripts to balance the equation.

9. 1,000,000,000 years.

10. A. 32
      B. 48
      C. 117
      D. 58
      E. 164

11. Because one mol of copper is 63. 6 g and one mol of sodium is 23.0 g. 

12. A. 6.02 X 10^23
      B. 3.01 X 10^23
      C. 0.602 X 10^23
      D. 39.1 X 10^23