JEE Main levelSingle correct optionDifficulty 2 of 3rx178
1.96 g of Mohr's salt, FeSOX4⋅(NHX4)X2SOX4⋅6HX2O (molar mass 392), is dissolved in dilute HX2SOX4 and titrated with 0.02 M KMnOX4. The volume of KMnOX4 required is:
A50 mL
B250 mL
C10 mL
D83.3 mL
Answer: A
Moles of Mohr's salt = 1.96/392 = 5 mmol, giving 5 meq of FeX2+ (n = 1). Normality of KMnOX4 = 0.10 N, so V=5/0.10=50 mL.