D.8-D.10

page 141

9.
a. 1Ca(PO4)2 + 3H2SO4---> 2H3PO4 + 3CaSO4
b. 2C8H18 + 25O2--->16CO2 +18H20

10.
a.
Na-2---->Na-1, 2
S-1------>S-1
O-4----->O-4
K-2----->K-2
CL-1,2--->Cl-1,2

b. NO he did not. He changed the subscript instead of changing the coefficient. This is VERY WRONG because in this way you are changing its identity, as you ruin the entire equation.

c. Na2SO4 + 2KCl ---> 2NaCl + K2SO4

11. An alloy is a solid solution consisting of atoms of two or more metals.