The product obtained as a result of the reaction between acetone and chloroform is used as:

Which of the following compounds will not undergo tautomerism?

When acetaldehyde is reacted with $LiAlH_4$,what is the product formed?

Which of the following reactions converts $Acetone$ into a hydrocarbon having the same number of carbon atoms?

Which of the following reactions will not result in the formation of carbon-carbon bonds?

Two aliphatic aldehydes $P$ and $Q$ react in the presence of aqueous $K_2CO_3$ to give compound $R$,which upon treatment with $HCN$ provides compound $S$. On acidification and heating,$S$ gives the product shown below:
$1.$ The compounds $P$ and $Q$ respectively are:
$2.$ The compound $R$ is:
$3.$ The compound $S$ is:
Give the answer for questions $1$,$2$ and $3$.