Identify the name of second higher homologue of formic acid?

What is the of number of chiral carbon atoms present in 2-Bromo-3,4,5-trimethylhexane ?

Which of the following alkyl chlorides on Wurtz reaction gives 2, 2, 5, 5- tetramethylhexane ?

Calculate the number of atoms present in $1\ \text{g}$ metal that forms simple unit cell structure if product of density and volume of unit cell is $66.5 \times 10^{-24}\ \text{g}$