Question

Ethylene glycol is used as an antifreeze in a cold cliamate Mass of ethylene glycol which should be added to `4` kg for water to prevent it from freezing at `-6^(@)C` will be (`K_(f)` for water =`1.86 K kg mol^(-1)` and molar mass of ethylene glycol =`62 g mol^(-1)`)
A. `800`g
B. `204.30`g
C. `400.00`g
D. `304.60`g

Answer 1

Correct Answer - A
`DeltaT_(f)` = Freezing point of `H_(2)O`-freezing point of ethylene glycol solution
`=0-(-6^(@))=6^(@)`
`K_(f)=1.86^(@)K kg mol^(-1)`
`w_(1)`=Mass of ethylene glycol in grams
`w_(2)`=Mass pf solvent `(H_(2)O)`in grams =`4000`g
`m_(1)`=Molar mass of ethylene glycol=`62mol^(-1)`
`DeltaT_(f)=(1000k_(f)w_(1))/(62xx4000)`
`w_(1)=800g`