In how many grams of water should 25.31 g of potassium nitrate (kno3) be dissolved to prepare a 0.1982 m solution?

Solution:

Molality:-It is a measure of the concentration of a solute in a solution in terms of amount of substance in a specified amount of mass of the solvent

Therefore,  

Molality = moles solute / kg solvent  

Therefore kg solvent = moles solute / molality  

moles solute = mass / molar mass  

= 25.31 g / 101.1 g/mole  

= 0.2503 mole

kg solvent = 0.2503 mole / 0.1982 m  

= 1.263 kg  

= 1263 g

This is the required answer.

where are the choice options?

4d^55s^1 ( third choice)