In group IV, white zinc ferrocyanide is obtained from a solution of Zn^2+ with excess K4[Fe(CN)6] as K2Zn3[Fe(CN)6]2. How many moles of K4[Fe(CN)6] are used per mole of Zn^2+ precipitated?

JEE Advanced levelSingle correct optionDifficulty 3 of 3qc105

In group IV, white zinc ferrocyanide is obtained from a solution of $Zn X^{2 +}$ with excess $K X_{4} [Fe (CN) X_{6}]$ as $K X_{2} Zn X_{3} [Fe (CN) X_{6}] X_{2}$ . How many moles of $K X_{4} [Fe (CN) X_{6}]$ are used per mole of $Zn X^{2 +}$ precipitated?

3 Zn X^{2 +} + 2 K X^{+} + 2 [Fe (CN) X_{6}] X^{4 -} K X_{2} Zn X_{3} [Fe (CN) X_{6}] X_{2}

is balanced (

6 + 2 - 8 = 0

). Two ferrocyanide units are used for every three

Zn X^{2 +}

, i.e.

2/3

mol of

K X_{4} [Fe (CN) X_{6}]

per mole of

Zn X^{2 +}