molality of a solution containing 0 85 gram of NH3 in 100 ml liquid of density 0 85 g /cm - Chemistry -

Question

molality of a solution containing 0 85 gram of NH3 in 100 ml liquid
of density 0 85 g /cm?

Balaram Shil · Accepted Answer

Dear Student,
Given,
Density = 0 85 g/cm3 = 0 85 g/0 001L = 85 g/0 1L
Therefore,
There are 0 85 grams of NH3 in
100cm3 ,i e, 0 85 g /0 1 L solution
Thus,
Mass of water in
solution (0 1L) = 85-0 85
= 84 15 g = 0 08415kg
Now,
Number of moles of NH3 = Mass/Molecular weight of
NH3
= 0 85/17 = 0 05mol
Hence,
Molality = Number of moles / mass of water in kg
= 0 05/0 08415
= 0 597 m

Regards,

molality of a solution containing 0.85 gram of NH3 in 100 ml liquid of density 0.85 g /cm?