A vitamin C tablet is dissolved and titrated with 0.0500 M iodine solution, C6H8O6 + I2 -> C6H6O6 + 2HI; 28.4 mL of the iodine solution is needed. Find the mass of ascorbic acid (molar mass 176) in the tablet in mg, to the nearest integer.

JEE Main levelNumerical answerDifficulty 2 of 3rx193

A vitamin C tablet is dissolved and titrated with 0.0500 M iodine solution, $C X_{6} H X_{8} O X_{6} + I X_{2} C X_{6} H X_{6} O X_{6} + 2 HI$ ; 28.4 mL of the iodine solution is needed. Find the mass of ascorbic acid (molar mass 176) in the tablet in mg, to the nearest integer.

Numerical answer type, answer in mg, tolerance 1.

mmol

I X_{2}

28.4 \times 0.0500 = 1.42

, equal to mmol ascorbic acid (1:1). Mass =

1.42 \times 176 = 249.92

mg, about 250 mg.