Isopropyl alcohol on oxidation gives

Which of the following reactions produces an organic product with the lowest boiling point?

Which one of the following gases is liberated when ethyl alcohol is heated with methyl magnesium iodide?

$HO-CH_2-CH_2-OH$ on heating with periodic acid gives:

$CH_3 CH_2 OH \underset{\text{step-}1}{\stackrel{Cl_2}{\longrightarrow}} CH_3 CHO$ $\underset{\text{step-}2}{\stackrel{3 Cl_2}{\longrightarrow}} Cl_3 CCHO$
In the above reactions,the role of $Cl_2$ in step-$1$ and step-$2$ respectively is:

Major product of the reaction is