Question

The density of 1M solution of NaCl is 2.5g/ml. Find molality of the solution​

Answer 1

Explanation:

Molarity = no. of moles of solute / volume of solution in L

Given, no. of moles of NaCl = 2.5g/ml

Density = Mass/ Volume

Mass of the solutuon = density x volume

= 2.5x 1000 = 2500

Mass of solute = mass of 3 moles of NaCl = 1x(23 +35.5) = 58.5

∴ mass of solvent = mass of solution - mass of solute

= 1250 - 175.5 = 2441.5g =2.4415kg

∴ molality = no. of moles of solute/ mass of solvent = 1/2.4415= 0.4095

∴ molarity = (molality x density x 1000 )- molar mass /1000

= (0.4095 x 2.5x 1000) -molar mass=result (you can calculate