In which of the following pairs, each member produces the same gas when reacted with water?

Options

A. `K , KO_(2)`
B. `Na, Na_(2)O_(2)`
C. `Ca, CaH_(2)`
D. `Ba, BaO_(2)`

Answer

C

Explanation

Both Ca, `CaH_(2)` react with `H_(2)O` to produce `H_(2)` gas .
`Ca + 2 H_(2) O to Ca(OH)_(2) + H_(2)`
`CaH_(2) + 2 H_(2)O to Ca(OH)_(2) + 2H_(2)`
In contrast , K reacts with `H_(2)O` to produce `H_(2)` but `KO_(2)` produces `O_(2)` (or `O_(2) + H_(2)O`) , Na produces `H_(2)` but `Na_(2)O_(2)` produces `O_(2)`. Similarly , Ba produces `H_(2)` but `BaO_(2)` produces `O_(2).`