How many chiral carbon atoms are present in 2-Iodo-3, 4, 5-trimethylhexane ?

Identify the product 'B' in the following reaction
$\text{Toluene} \xrightarrow{\large{\text{Chromyl chloride} / \text{CS}_2}} A \xrightarrow{\large{\text{H}_3\text{O}^+}} B$

Identify the 'A' in the following reaction.
$\text{CaC}_2 + \text{H}_2\text{O} \rightarrow \text{A} + \text{Ca(OH)}_2$

Calculate the number of atoms in 1 g metal that forms bcc crystal structure $[\rho \times a^3 = 6 \cdot 6 \times 10^{-22} \text{ g}]$