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Calculate the mass of ascorbic acid (Vitamin C, C_6 H_8 O_6) to be dissolved in 75 g of acetic acid to lower its melting point by 1 point 5 degree C Kf = 3.9 K kg mol to the power of -1

2.11 . Calculate the mass of ascorbic acid (Vitamin C, C_{6}H_{8}O_{6} ) to be dissolved in 75 \; g of acetic acid to lower its melting point by 1.5^{\circ}C.           K_{f}=3.9\; K\; kg\; mol^{-1}

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Elevation in melting point = 1.5 degree celsius.

Here we will use the following equation :

                                               \Delta T_b = \frac{K_b\times 1000\times w_2}{M_2\times w_1}

Putting given values in the above equation :

                                               w_2 = \frac{1.5\times176\times75}{3.9\times1000} = 5.08\ g

Thus 5.08 ascorbic acid is needed for required condition.

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