What is the number of moles of $$\mathrm{sp}^2$$ hybrid carbon atoms in one mole of hexa-1,4-diyne?

What is the number of moles of water molecules required to prepare n moles of methane from n moles of methyl magnesium iodide?

Identify the product A in the following reaction.

Which of the following catalyst/reagent is used to convert $$\mathrm{C} \equiv \mathrm{C}$$ triple bond to $$\mathrm{C}=\mathrm{C}$$ double bond to form cis isomer of alkene?