What is the molality of a solution that contains. 500 mol hc2h3o2 and 0.125 kg h2o?

Molality is defined as the number of moles of solute in 1 kg of solvent

in this case solvent is H₂O and solute is HC₂H₃O₂

number of moles of solute - 0.500 mol

mass of solvent - 0.125 kg

since we need to know how many moles in 1 kg solvent

if 0.125 kg contains - 0.500 mol

then 1 kg contains - 0.500 mol / 0.125 kg = 4 mol

therefore molality of solution is 4 mol/kg