Question

When the following oxidation-reduction equation representing a reaction that takes
place in BASIC solution is correctly balanced using the smallest possible whole number
coefficients, the coefficient before the Al is:
Al + NO2
- = Al(OH)4
- + NH3

Answer 1

Solution.

$Al^0 + NO2^- = Al(OH)4^- + NH3$

$Al^0 + 4OH^- = Al(OH)4^- + 3e$

$NO2^- + 5H2O + 6e = NH3 + 7OH^-$

$2Al^0 + NO2^- + OH^- + 5H2O = 2Al(OH)4^- + NH3$

Answer:

$2Al^0 + NO2^- + OH^- + 5H2O = 2Al(OH)4^- + NH3$