Question

what is the formulae for solving molality problems

Answer 1

molatity :- molatity is the no of mole present in 1 kg of solvent . it is denoted by m .

e.g
m = no of mole of solute/weight of solvent ( in kg) .

m = w × 1000/( M × M")

where w = given weight of solute
M = molecular weight of solute ( in g )
M" = weight of solvent ( in g)


also , very important of relationship molatity , molarity and density is

1/m = d/M - Ms/1000

where m = molatity
M = molarity
Ms = molar weight of solute
d = density of solution.

Answer 2

Molaliti(m) = {w'B (g)× 1000}/{m'B × w'A(g)}
where,w'B = mass of solute in gram.
= m'B = molar mass of solute .
= w'A = mass of solvent in gram