Answer:
1.14mol/kg
Explanation:
Mass of solute = 0.2kg
Mass of solvent = 3kg
Molality = no. Of moles / kg of solvent.
0.2 kg of NaCl = x moles
No. Of moles = mass / molarmass.
Molar mass of Na = 23
Molar mass of Cl = 35.5
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
0.2kg = 0.2 × 1000g = 200g.
No. Of moles = 200 / 58.5
No. Of moles = 3.419moles.
Molality = no. Of moles / kg of solvent.
Molality = 3.419 / 3.0
Molality = 1.139 mol/kg = 1.14mol / kg
