Question

Ethylene glycol (CH₂OHCH₂OH)is a major component of permanent antifreeze, effectively depresses the freezing point of water in an automobile radiator. What minimum weight of ethylene glycol must be mixed with 6 gallon of water to protect it from freezing at 24 degree Celsius? K_f= 1.86, 1 gallon=3.785

Answer 1

$$\begin{gathered} ∆T_f=K_{f}m \\ =K_f\frac{W_2}{M_2\times W_1}\times 1000 \\ Givenvolumeofthesolvent=3.785L \\ 24=1.86\frac{W_2}{62\times 3.785}\times 1000(\sin cedensityofwater=1g/mL:Massofwater=volumeofwater) \\ {W}_2=\frac{62\times 3.785\times 24}{1.86\times 1000}=3.028g \end{gathered}$$