Which of the following compounds has the most acidic hydrogen?

In which of the following reactions,two products will be formed other than triphenylphosphine oxide $(Ph_3PO)$?

When acetone is heated with hydroxylamine,the compound formed is

An organic compound $A$ reacts with methyl magnesium iodide to form an addition product,which on hydrolysis gives compound $B$. Compound $B$ gives a blue color in the Victor Meyer test. What are compounds $A$ and $B$ respectively?

Which one of the following compounds will give dimethyl glyoxal with $SeO_2$?

$A$ carbonyl compound $X$ $(C_8H_8O)$ undergoes disproportionation with conc. $KOH$ on heating. The product of $X$ with $Zn-Hg/HCl$ is $Y$ and the product of $X$ with $NaBH_4$ is $Z$. What are $Y$ and $Z$ respectively?