In basic solution stannite reduces bismuth(III) hydroxide to bismuth: Bi(OH)3 + SnO2^2- -> Bi + SnO3^2- + H2O. In the balanced equation (smallest whole numbers) the coefficient of H2O is

JEE Main levelSingle correct optionDifficulty 2 of 3rx057

In basic solution stannite reduces bismuth(III) hydroxide to bismuth: $Bi (OH) X_{3} + SnO X_{2} X^{2 -} Bi + SnO X_{3} X^{2 -} + H X_{2} O$ . In the balanced equation (smallest whole numbers) the coefficient of $H X_{2} O$ is

Bi gains 3 electrons per atom and Sn (+2 to +4) loses 2, so Bi : Sn = 2 : 3. Hydroxide and oxygen counts then balance with 3

H X_{2} O

on the right:

2 Bi (OH) X_{3} + 3 SnO X_{2} X^{2 -} 2 Bi + 3 SnO X_{3} X^{2 -} + 3 H X_{2} O