Balance the following redox equation without using partial ionic equations: $HNO_3$ $+$ $H_2S$ $\longrightarrow$ $H_2O$ $+$ $NO$ $+$ $S_8$ - Look for the atoms whose oxidation number changes ! - How many electrons are exchanged by each of those atoms?
o.n.(N): $5$ → $2$ : $3 e^-$ exchanged by each $N$ atom. o.n.($S$): $-2$ → $0$ : $2 e^-$ exchanged by each S atom.
How many electrons are exchanged by a molecule containing these atoms?
$3 e^-$ exchanged by $HNO_3$ $16 e^-$ exchanged by $S_8$.
What is the ratio of these molecules? Finish the balancing!
Ratio 16:3 $16$$HNO_3$ $+$ $24H_2S$ $\longrightarrow$ $32H_2O$ $+$ $16NO$ $+ $3$$S_8$