Identify the hetero atom and number of double bonds respectively present in furan?

Identify compound A from following reaction.

$$\mathrm{A}+\mathrm{C}_2 \mathrm{H}_5 \mathrm{MgBr} \xrightarrow[\text { ety }]{\text { drer }} \mathrm{B} \xrightarrow{\mathrm{H}_3 \mathrm{O}^{+}} \text {3-methylpentan-3-ol }$$

How many hydrogen atoms are bonded to ammonium ion during solvation?

What is the weight of $$\mathrm{Al}$$ deposited at cathode when 1 ampere current is passed through molten $$\mathrm{AlCl}_3$$ for 9650 seconds? (At mass of $$\mathrm{Al}=27$$)