Which sample will process the greatest mass of hydrogen when treated with water: a) CaH2 b) LiH c) MgH2 d) NaH

Question

Group I and Group II ionic hydrides react to water and produces the hydrogen -

H (s) + H2O (l) = OH (l) + H2 (g)

In an experiment if the 1gm sample of each of the following five ionic hydrides are mixed are treated with excess of water. Which sample will process the greatest mass of hydrogen

a) CaH2
b) LiH
c) MgH2
d) NaH

Answer 1

Ans is (b) LiH has the highest atomic ratio of H/Li

Comments

Why??

Answer 2

the atomic masses of H, Ca , Li, Mg and Na are 1, 20, 3, 12 and 11. Rest is basic chemistry