490g of Na2SO4 are dissolved in 80g of water. Determine the molality of this solution

43.13mol/kg

Explanation:

since molality is the concentration of a solution in moles of solute per kilogram of solvent.

moles of Na2SO4 = mass/molar mass

= 490/142

= 3.45 mol

mass of water in kg= 80/1000

=0.08kg

molality is therefore= 3.45/0.08

=43.5mol/kg

the awnser is group 12

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.