Pyruvic acid is obtained by

The reaction $CH_3-CH=CH_2 \xrightarrow[H^{+}]{CO + H_2O} CH_3-CH(COOH)-CH_3$ is known as:

In the above reaction,the reagent $A$ is :

Which of the following reagents is the correct sequence for the conversion of $R-CH_2-CH_2OH$ to $R-CH_2-CH_2-COOH$?

In the reaction $CH_3CN \xrightarrow{H_3O^+, \text{heat}} CH_3COOH$,what is the change in the hybridization state of the functional carbon atom?

Toluene on reaction with reagent $A$ gives $X$. This $(X)$ forms $2,4-$dinitrophenylhydrazone and reduces ammonical silver nitrate solution. Reaction of toluene with another reagent $B$ forms $Y$,which dissolves in $NaHCO_3$ with evolution of $CO_2$. What are $A$ and $B$ respectively?