Calcium hydride reacts with water: CaH2 + 2H2O -> Ca(OH)2 + 2H2. Which statement is correct?

Hydridic H (-1) is oxidised to 0 and water H (+1) is reduced to 0, so H2 is both the oxidation and reduction product

CaH2 is the oxidising agent because H goes from -1 to 0

Hydridic H (-1) is oxidised to 0 and water H (+1) is reduced to 0, so H2 is both the oxidation and reduction product

Water is oxidised because oxygen goes from -2 to 0

JEE Advanced levelSingle correct optionDifficulty 3 of 3rx041

Calcium hydride reacts with water: $CaH X_{2} + 2 H X_{2} O Ca (OH) X_{2} + 2 H X_{2}$ . Which statement is correct?

A $CaH X_{2}$ is the oxidising agent because H goes from $- 1$ to $0$
BCa is oxidised from $0$ to $+ 2$
CHydridic H ( $- 1$ ) is oxidised to $0$ and water H ( $+ 1$ ) is reduced to $0$ , so $H X_{2}$ is both the oxidation and reduction product
DWater is oxidised because oxygen goes from $- 2$ to $0$

CaH X_{2}

, H is

- 1

and Ca is

+ 2

(unchanged). H in

H X_{2} O

+ 1

. Both go to

0

H X_{2}

: hydride loses electrons (oxidised, so

CaH X_{2}

is the reducing agent) and water H gains (reduced). Oxygen stays at

- 2