Which of the following gases is formed during the oxidation of trichloromethane?

Which is the most reactive halide towards $S_{N^1}$ reaction?

An unknown compound $A$ has the molecular formula $C_5H_9Cl$. It does not react with $Br_2 / CCl_4$. When treated with a strong base,it gives a compound $B$ with the molecular formula $C_5H_8$,which reacts with $Br_2 / CCl_4$. Ozonolysis of $B$ followed by treatment with dimethyl sulfide gives a compound with the molecular formula $C_5H_8O_2$. What is the structure of $A$?

Which of the following does not form a Grignard reagent?

Which of the following is an incorrect statement?

The increasing order of densities of the following alkyl halides is:
$(I)$ $n-C_3H_7Br$
$(II)$ $n-C_3H_7Cl$
$(III)$ $n-C_3H_7I$