Which of the following is an industrial fuel?

Which one of the following properties is generally not applicable to ionic hydrides?

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R).$
Assertion $(A):$ Heavy water is used for the study of reaction mechanism.
Reason $(R):$ The rate of reaction for the cleavage of $O-H$ bond is slower than that of $O-D$ bond.
Choose the most appropriate answer from the options given below:

An alkali metal hydride $(NaH)$ reacts with diborane in '$A$' to give a tetrahedral compound '$B$' which is extensively used as a reducing agent in organic synthesis. The compounds '$A$' and '$B$' respectively are

Give the reaction of methane with steam for the production of dihydrogen.

Which of the following gases is insoluble in water?