Question

$HCHO\underset{Conc.NaOH}{\overset{}{\to }}\left(x\right)+\left(y\right)$
Oxidation number of carbon changes from ?

• A. $Oto+1and0to-2$
• B. $0to+1and0to-1$
• C. $0to+2and0to-2$
• D. $None$

Answer 1

The correct option is C $0to+2and0to-2$

Formaldehyde( no alpha hydrogen atom) when react with NaOH, the reaction is called Cannizzaro reaction.

$2HCHO+NaOH⟶HCOONa+C{H}_{3}OH$

A B C

Oxidation state of C from A to B

For A oxidation state is

4+2x+-4=0

x=0

For B oxidation state of C is

1+x-4+1=0

x=2

For C oxidation state of C(CARBON) is

X+4-2=0

X=-2