Question

A solution of glucose (molar mass = 180) in water is labelled as 10% by mass what would be the motality and molarity of the solution (deurity of solution = 1.2g /ml) ​

Answer 1

Answer:

Explanation:

10% by mass means 10g glucose in 90g H20

So moles of glucose = 10/180 = 1/18 moles

density of solution = 1.2g/ml = m/v

Total mass of solution = 100g

Let volume be v

So 1.2 = 100/v

v =  100/1.2 (in ml)

Molarity = no. of moles of solute/ volume of solution (in l)

M = 1/18 /100/1.2 X 1000 (in l) = 1.2 * 1000/18 * 100

M = 2/3 = 0.66 M

Molality = no of moles of solute / weight of solvent in kg

m = 1/18 / 90 * 1000 = 0.617 m