Discussion Forum

A compound  H₂X with molar weight of 80g is dissolved in a solvent having density of 0.4g ML^-1. Assuming no change in volume upon dissolution, the molality  of a 3.2  molar solution is

Answer:

Explanation:

 Plane  This problem can be solved by using concept of conversion of molarity into molality.

Molarity=3.2 M

 Let  volume  of solution=1000mL=volume of solvent

 Mass of solvent =1000 x 0.4 =400g

 Since, molarity of solution is 3.2 molar

  $\therefore$       $ n_{solute}=3.2 mol$

 Molality (m)=  $\frac{3.2}{400/1000}=8$

 Hence, correct integer is (8)