Which among the following is NOT dicarboxylic acid?

What is IUPAC name of following compound?

Consider the following cell $\mathrm{E}^{\circ}$ cell $=1.007 \mathrm{~V}$ and $\mathrm{E}^{\circ}$ calomel $=0.242 \mathrm{~V}$ What is the standard potential of Zn ?

Identify the substrate ' A ' in the following conversion.

$$A \xrightarrow[\mathrm{H}_3 \mathrm{O}^{+}]{\mathrm{AlH}(\mathrm{~i-Bu})_2} \text { Pent-3-enal }$$