Which one of the following chemical agents is not used for the dry-cleaning of clothes?

$O_2F_2$ is an unstable yellow-orange solid and $H_2O_2$ is a colourless liquid. Both have an $O-O$ bond. The $O-O$ bond length in $H_2O_2$ and $O_2F_2$ respectively is:

What is the concentration of $20$ volume $H_2O_2$ in $g/L$?

Electrolysis of $X$ gives $Y$ at anode. Vacuum distillation of $Y$ gives $H_2O_2$. The number of peroxy $(O-O)$ bonds present in $X$ and $Y$ respectively are :

Which of the following liberates $O_2$ upon hydrolysis?

When $2-$ethylanthraquinol dissolved in a mixture of benzene and cyclohexanol is oxidised,the product is