F.4 平衡化學方程式

16
it is a acid-base reaction.
1. right-hand-side has 3 NO3-, so there should be 3 HNO3
2. there are 3 OH- ion in left-hand-side, there should be 3 H2O after neutralization.

Al(OH)3 + 3 HNO3 --------> 3 H2O + Al(NO3)3


17
it is a redox reaction: K being oxidized into K+
write down the half-equation of oxidation:
K ----> K+ + e-

half-equation of reduction:

2 H2O + 2 e- ----> H2 + 2 OH-

since the reduction needs 2 e-, multiply the stociometry in oxidation with 2 and the overall reaction will be:

2 H2O + 2 K --------> H2 + 2 KOH