In ethers,the $C-O-C$ bond angle is ........ $^{\circ}$

Which of the following compounds is obtained when anisole is heated with dilute sulfuric acid?

$A$ mixed ether $(P)$,when heated with excess of hot concentrated hydrogen iodide,produces two different alkyl iodides which when treated with aqueous $NaOH$ give compounds $(Q)$ and $(R)$. Both $(Q)$ and $(R)$ give a yellow precipitate with $NaOI$. Identify the mixed ether $(P)$:

The major product formed in the following reaction is: $CH_{3}Br + CH_{3}CH_{2}ONa \longrightarrow$

In which of the following reactions is the product an ether?

$Tert$-butyl methyl ether on treatment with hydrogen iodide in cold gives