question_answer

The correct statements among [a] to [b] are: [JEE Main 10-4-2019 Afternoon]

[a] saline hydrides produce \[{{H}_{2}}\]gas when reacted with \[{{H}_{2}}O\].

[b] reaction of \[LiA{{H}_{4}}\]with \[B{{F}_{3}}\]leads to \[{{B}_{2}}{{H}_{6}}.\]

[c] \[P{{H}_{3}}\] and \[C{{H}_{4}}\] are electron - rich and electron precise hydrides, respectively.

[d] \[HF\]and \[C{{H}_{4}}\]are called as molecular hydrides.

A) [c] and [d] only

B) [a], [b] and [c] only

C) [a], [b], [c] and [d]

D) [a], [c] and [d] only

Correct Answer: C

Solution :

[a] \[\underset{Ionichydride/salinehydride}{\mathop{\overset{\oplus }{\mathop{M}}\,\overset{\Theta }{\mathop{H}}\,+HOH}}\,\xrightarrow[{}]{{}}MOH+{{H}_{2}}\] [b]\[4B{{F}_{3}}+3LiAl{{H}_{4}}\xrightarrow[{}]{{}}2{{B}_{2}}{{H}_{6}}+3LiF+3Al{{F}_{3}}\] [c]\[\to \]phosphorous is electron rich hydride due to presence of lone pair \[\to \]It is electron precise hydride. [d] \[HF\And C{{H}_{4}}\]are molecular hydride due to they are covalent molecules.