The order of basicity among the following compounds is

Upon heating $$KCl{O_3}$$ in the presence of catalytic amount of $$Mn{O_2},$$ a gas $$W$$ is formed. Excess amount of $$W$$ reacts with white phosphorous to give $$X.$$ The reaction of $$X$$ with pure $$HN{O_3}$$ gives $$Y$$ and $$Z.$$

$$Y$$ and $$Z$$ are, respectively

Which of the following combination will produce $${H_2}$$ gas ?

For the following compounds, the correct statement(s) with respect to nucleophilic substitution reaction is (are)