Question

Among the following, what is the total number of compounds having zero oxidation state of the underlined elements?
a. $\underset{–}{S}{O}_3^{2-}$
b. $H_2\underset{–}{C}O$
c. $\underset{–}{C}{H}_2{Cl}_2$
d. ${Na}_2\underset{–}{{Cr}_2}{O}_7$
e. $\underset{–}{O_3}$

Answer 1

The total number of compounds having zero oxidation state of the underlined elements is $+3$.
The zero oxidation state of the underlined element is in (b) $H_2\underset{–}{C}O$, (c) $\underset{–}{C}{H}_2{Cl}_2$ and (e) $\underset{–}{O_3}$.
The compounds and the oxidation states of the underlined elements are shown below:
a. $\underset{–}{S}{O}_3^{2-}$ $+4$
b. $H_2\underset{–}{C}O$ $0$
c. $\underset{–}{C}{H}_2{Cl}_2$ $0$
d. ${Na}_2\underset{–}{{Cr}_2}{O}_7$ $+6$
e. $\underset{–}{O_3}$ $0$