Which of the following halogen derivatives forms poisonous phosgene gas when it comes in contact with air and light?

The major product of the reaction between $CH_{3}CH_{2}ONa$ and $(CH_{3})_{3}CCl$ in ethanol is

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A):$ $R-I$ undergoes $S_N2$ reaction faster than $R-Cl$.
Reason $(R):$ Iodine is a better leaving group because of its large size.
In the light of the above statements,choose the correct answer from the options given below:

Which of the following chloro compounds has a dipole moment?

The major product obtained in the following reaction is $C_2H_5ONa + (CH_3)_3C-Cl \rightarrow$

What is the product formed when $n$-propyl bromide is reacted with ethanolic potassium hydroxide?