Question

Consider the following reaction:

$HCHO + 2\lbrack Ag(NH_{3})_{2}\rbrack^{+} + 3OH^{-} \rightarrow 2Ag + HCOO^{-}$

$+ 4NH_{3} + 2H_{2}O$

Which of the following statements regarding oxidation and reduction is correct?

• A. HCHO is oxidized to $HCOO^{-}$and $\lbrack Ag(NH_{3})_{2}\rbrack^{+}$is reduced to Ag.
• B. HCHO is reduced to $HCOO^{-}$and $\lbrack Ag(NH_{3})_{2}\rbrack^{+}$is oxidized to Ag.
• C. $\lbrack Ag(NH_{3})_{2}\rbrack^{+}$ is reduced to Ag while $OH^{-}$is oxidized to $HCOO^{-}$
• D. $\lbrack Ag(NH_{3})_{2}\rbrack^{+}$ is oxidized to $NH_{3}$while HCHO is reduced to $H_{2}O.$

Answer 1

Answer: (A)

HCHO is oxidized to $HCOO^{-}$and $\lbrack Ag(NH_{3})_{2}\rbrack^{+}$is reduced to Ag.

Answer 2

: $HC ⥂ HO + 2\left\lbrack Ag(NH_{3})_{2} \right\rbrack^{+} + 3OH^{-} \rightarrow$

$2Ag + HCOO^{-} + 4NH_{3} + 2H_{2}O$

$HCHO \rightarrow HCOO^{-}$ (oxidation)

$\lbrack Ag(NH_{3})_{2}\rbrack^{+} \rightarrow$Ag (reduction)