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. `800.00 g`
B. `204.30 g`
C. `400.00 g`
D. `304.60g`

Answer 1

Correct Answer - A
`Delta T_(f) = K_(f) xx "molality" = K_(f) xx (w xx 1000)/(m xx W)`
`w = ?, W = 4 xx 10^(3)g, m = 62`
`Delta T_(f) = 0-(-6) = 6`
`w = (6 xx 62 xx 4 xx 10^(3))/(1000 xx 1.86) = 800 g`