After adding non-volatile solute freezing point of water decreases to -`0.186^@C`. Calculate `DeltaT_b` if `K_f = 1.86 K kg mol^(-1)`and `K_b = 0.521 K kg mol^(-1)`

Options

A. `0.0521`K
B. `0.0186` K
C. `0.521 `K
D. `1.86` K

Answer

A

Explanation

`DeltaT_(f) = T_(f) = T_(f)^(@) - T_(f) = 0 - (-0.186) = 0.186 ^(@)C`
`DeltaT_(f) = K_(f) xx m `
` rArr m = (DeltaT_(f))/(K_(f)) = (0.186)/(1.86) = 0.1 m `
` DeltaT_(b) = K_(b) xx m = 0.521 xx 0.1 = 0.0521 K `