Q. 114.3( 17 Votes )
Calculate the mass of ascorbic acid (Vitamin C, C6H8O6) to be dissolved in 75 g of acetic acid to lower its melting point by 1.5°C. Kf = 3.9 K kg mol-1.
Mass of acetic acid, w1 = 75 g
Lowering of melting point, ΔTf = 1.5 K
Kf = 3.9 K kg/mol
Molar mass of ascorbic acid (C6H8O6), M2 6 × 12 + 8 × 1 + 6 × 16 = 176 g/mol
We know that,
= 5.08 g
5.08 g of ascorbic acid is needed to be dissolved.
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