

InterviewSolution
Saved Bookmarks
1. |
A compound `H_(2)X` with molar mass of `80 g` is dissolved in a solvent having density of `0.4 g mL^(-1)`. Assuming no change in volume upon dissolution, the molality of a `3.2` molar solution isA. `9`B. `6`C. `5`D. `8` |
Answer» Correct Answer - 4 Since these is no change in volume upon dissolution, the volume of solution is nearly equal to the volume of solvent. 3.2 molar solution implies that 3.2 moles of solute are present in every one litre of solution. Thus considering 1L of solution we have 3.2 moles of solute. Mass of solvent=(Volume of solvent)(Density of solvent) `=(1000 mL)(0.4 g mL^(-1))` `=400 g` `=0.4 kg` Thus, molarity (m)`=("moles of solute")/("mass of solvent" (kg))=(3.2 mol)/(0.4 kg)` `=8 mol kg^(-1)` |
|