JEE Main20199 Apr 2019Evening ShiftChemistrySome Basic Concepts of ChemistryActual

What would be the molality of 20% (mass/mass) aqueous solution of K I ? (molar mass of K I = 166 g m o l - 1 )

Options

A1.35
B1.51
C1.08
D1.48

Correct answer

B. 1.51

Step-by-step solution

Molality = M o l e s   o f   s o l u t e w e i g h t   o f   s o l v e n t g × 1000 100   g m of solution contains 20   g m   K I So, the moles of K I = 20 166 Weight of solvent = 100 - 20 = 80   g m Molality = 20 × 1000 166 × 80 = 1.51   M o l a l

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