(3) How much ZnCl2 is formed by using 50 g. HCl? The question
is now between HCl and ZnCl2.

Zn + 2HC1 = ZnCl2 + 2H
73 136 | Arrange the proportion, and solve.
50 x

Suppose we have generated H by using H2S04: the equation is
Zn + H2S04 = ZnSO4 + 2 H. There is the same relation as before
between the quantities of Zn and of H, but the H2S04 and ZnS04 are
different.

How much H2SO4 is needed to generate 12 g. H?

Zn + H2SO4 = ZnS04 + 2 H
98 2 | Make the proportion, and solve
x 12

Solve:--

(1) How much H in 200 g. H2S04?

(2) How much ZnS04 is produced from 200 g. H2S04?
(3) How much H2S04 is needed for 7 1/2 g H?
(4) How much Zn will 40 g. H2SO4 combine with?
(5) How much Fe will 40 g. H2SO4 combine with?
(6) How much H can be obtained by using 75 g Fe?

These principles apply to all reactions. Suppose, for example, we