Calculate the molality of a 20.0 percent by weight aqueous solution of nh4cl. (molecular weight: nh4cl = 53.5)

Explanation:

If we have a 20% by weight solution indicates that in 100 g of solution we have 20 g of . So, in the 100 g of solution we will have 80 g of (100-20= 80). If we remember the molality equation:

On this case the solute is , so we have to convert from g to mol using the molar mass:

Then we have to calculate the Kg of solvent (), so:

Finally, we have to divide these two values: