## Chemistry and Chemical Reactivity (9th Edition)

Per kg of mixture: Mass of acetic acid: $5\%\times 1\ kg = 0.05\ kg=50\ g$ The molar mass of acetic acid: $1.008|_H\times4+12.011|_C\times2+15.999|_O\times2=60.052\ g/mol$ Number of mols of acetic acid: $50\ g\div60.052\ g/mol=0.833\ mol$ Mass of water: $(100-5)\%\times1\ kg=0.95\ kg$ Molality: $0.833\ mol\div0.95\ kg=0.876\ molal$