Question

25 mL of 0.08 N Mohr's salt solution is oxidised by 20 mL of $K_2Cr_2O_7$ in acidic medium. The mass of Mohr's salt present in 500 cc is

• A. 3.96 g
• B. 15.68 g
• C. 39.6 g
• D. 39.2 g

Answer 1

Answer: (B)

15.68 g

Answer 2

0.08 N of Mohr's salt= 0.08 M
No. of moles in 25 mL of 0.08 M Mohr's salt solution
$= 0.08 \times \frac{25}{1000} = 0.002$
No. of moles in 500 cc of Mohr's salt solution
$0.002 \times \frac{500}{25} = 0.04$
Hence, mass of Mohr's salt present in 500 cc
$= 0.04 \times 392 = 15.68 g$