Find the molarity of 1.15 g KF in 150 mL of water

Answer 1

molality=moles solute / kg solvent

solute = KF

solvent = water

moles solute;

Convert grams to moles with the molar mass

molar mass = K + F = 39.1+19.00

1.5 g / (molar mass) = moles

1.5/(39.1+19.00)=moles

solvent:

water has a density of 1g/mL, so 150mL=150g.

1000g=1kg, so

(150g/1)(1kg/1000g)=0.150 kg

molality=^{1.5/(39.1+19.00)moles}/_0.150kg