In the following transformation,reagents $1$ and $2$ are:

Which of the following can undergo Hell-Volhard-Zelinsky reaction?

$CH_3MgBr$ (excess) + $EtO-C(=O)-OEt$ $\xrightarrow{(2) H^{+}}$ $(A)$; Product $(A)$ is:

Which of the following is most acidic?

In the given reaction,the reactant is $\gamma$-valerolactone. Predict the product $[X]$ for the reaction: $\text{Reactant} \xrightarrow{H_2O/H^{+}} [X]$.

Oxalic acid reacts with concentrated $H_2SO_4$ to give a mixture of two gases. When this mixture is passed through caustic potash,one of the gases is absorbed. What is the product formed by the absorbed gas with caustic potash?