The molar ratio of Cr 2+ to Cr 3+ in a mixture of CrSO 4 and Cr 2( SO 4)3 having equal number of in both sulphates is

Question

The molar ratio of Cr 2+ to Cr 3+ in a mixture of CrSO 4 and Cr 2( SO 4)3 having equal number of in both sulphates is (A) 1: 3 (B) 3: 2 (C) 2: 3 (D) 3: 4

Tardigrade Admin · Accepted Answer

CrSO 4 arrow Cr 2++ SO 42- Cr 2( SO 4)3 arrow 2 Cr 3++3 SO 42- Cr 2+ arrow SO 42- ∵ Sulphates are equal in number 2 Cr 3+ arrow 3 SO 42- ∴ ( Cr 2+/ Cr 3+)=3: 2

Q. The molar ratio of $C r^{2 +}$ to $C r^{3 +}$ in a mixture of $C r S O_{4}$ and $C r_{2} (S O_{4})_{3}$ having equal number of in both sulphates is

$1 : 3$

$3 : 2$

$2 : 3$

$3 : 4$

$C r S O_{4} \to C r^{2 +} + S O_{4}^{2 -}$

$C r_{2} (S O_{4})_{3} \to 2 C r^{3 +} + 3 S O_{4}^{2 -}$

$C r^{2 +} \to S O_{4}^{2 -}$

$∵$ Sulphates are equal in number

$2 C r^{3 +} \to 3 S O_{4}^{2 -}$

$∴ \frac{C r ^{2 +}}{C r ^{3 +}} = 3 : 2$

Q. The molar ratio of Cr2+ to Cr3+ in a mixture of CrSO4​ and Cr2​(SO4​)3​ having equal number of in both sulphates is

1:3

3:2

2:3

3:4