Iodoform can be prepared from all,except

An alcohol $X$ $(C_4H_{10}O)$ on dehydration gives an alkene $(C_4H_8)$ as the major product,which on bromination followed by treatment with $Y$ gives an alkyne $C_4H_6$. The alkyne $C_4H_6$ does not react with sodium metal. What are $X$ and $Y$?

Which of the following compounds has the highest boiling point?

$A \xrightarrow{KOBr} CHBr_3$
Here $A$ is:

What is the product of the oxidation of ethyl alcohol with $K_2Cr_2O_7$?

Statement-$1$ : Secondary $\&$ Tertiary alcohols can be distinguished by Lucas reagent.
Statement-$2$ : Secondary $\&$ Tertiary alcohols can be distinguished by dichromate test.