Question

Oxidation state of carbon in compound $A$ is:

• A. $+1$
• B. $+4$
• C. $-4$
• D. $+2$

Answer 1

Answer: (C)

$-4$

Disproportionate reaction in electric furnace.

$2B_2{O}_3+7C\underrightarrow{t^{\circ }C}6CO+B_{4}C⟶A$ is harder than diamond

$\downarrow$ $\downarrow$ $\downarrow$

$0$ $+2$ $-4$

$\downarrow$ {oxidation states}

oxidation state

Boron can exhibit $+1$ oxidation state in lower cases

The oxidation state of carbon in compound $A$ is $-4$

$\downarrow$

$\left(B_{4}C\right)$