Question

A solution of glucose (molar mass=180) in water is labelled as10%(by mass).what would be the molality and molarity of the solution.
Density of solution=1.2gmol -1

Answer 1

use formula,
molatity =(W/w weight percent ) x 10 x density of solution/Msolute

given,
W/w % = 10%
d = 1.2 g/mol
Msolute = 180g

now ,
molarity = 10× 10 × 1.2/180
=120/180
=2/3
=0.667M

use formula,

1/molatity = d/M - Msolute/1000

d is the density of solution
M is the molarity
now,

1/m = 1.2/(2/3) - 180/1000

1/m = 1.8 - 0.18

1/m = 1.62

m = 1/1.62