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Which solution is more concentrated- one molal solution or one molar solution?
             

Depends on specific gravity.

molarity = moles/volume in litres of the solution
Volume = mass of solution / density of solution                                                                                         
so Molarity equation changes like this
molarity = moles * density / mass of the solution
or moles = molarity *mass of solution / density ---(1)
Molality = moles/kg of the solvent
moles = molality * kg of the solvent ----(2)
Now we can say if moles are in the solution
molarity *mass of solution / density  =  molality * kg of the solvent
or (molarity *mass of solution / density )/ kg of the solvent = molality
mass of solution (W_sol )
mass of the solvent (W_solvent)
molality ---m
molarity --M
M *W_sol/( d * W _solvent) = m
Now let us analyze :
W sol > W solvent
If solution is very dilute then W_solution = W _solvent
Now if density = 1 g/mL
in that case M is nearly same as molality or we can say Molarity slightly greater then molality
However if density >1 then Molarity > molality
However if density is less than 1 then molality > molarity
So we can say in water where density is 1 and solutions are dilute -molality = molarity
In case of dense solution where density is more than 1 , molarity is always greater than molality
In less dense solution where density is less than 1,molality is always greater than molarity.

Thanks for the lecture.
But this is what I mentioned above,it depends of the specific gravity.

Quote from: chenbeier on August 29, 2021, 10:01:24 AM
Thanks for the lecture.
But this is what I mentioned above,it depends of the specific gravity.

It is not the answer of the question posted by student. We need to explain why and how also