Tert-butyl alcohol is a solvent with a kf of 9.10 ∘c/m and a freezing point of 25.5 ∘c. when 0.807 g of an unknown colorless nonelectrolyte liquid was dissolved in 11.6 g of tert-butyl alcohol, the solution froze at 15.3 ∘c. which of the following is most likely the identity of this unknown liquid? view available hint(s) tert-butyl alcohol is a solvent with a of 9.10 and a freezing point of 25.5 . when 0.807 of an unknown colorless nonelectrolyte liquid was dissolved in 11.6 of tert-butyl alcohol, the solution froze at 15.3 .which of the following is most likely the identity of this unknown liquid? ethylene glycol (molar mass = 62.07 g/mol) 1-octanol (molar mass = 130.22 g/mol) glycerol (molar mass = 92.09 g/mol) 2-pentanone (molar mass = 86.13 g/mol) 1-butanol (molar mass = 74.12 g/mol)

ethylene glycol (molar mass = 62.07 g/mol).

Explanation:

ΔTf = Kf.m,

ΔTf is the depression in the freezing point of tert-Butyl alcohol (ΔTf = freezing point of pure solvent - freezing point in presence of unknown liquid = 25.5°C - 15.3°C = 10.2°C).

Kf is the molal freezing point constant of tert-Butyl alcohol (Kf = 9.1 °C/m).

m is the molality of unknown liquid.

∵ ΔTf = Kf.m

∴ m = ΔTf/Kf = (10.2°C)/(9.1 °C/m) = 1.121 m.

Molality (m) is the no. of moles of solute in 1.0 kg of solvent.

∴ m = (mass/molar mass) of unknown liquid/(mass of tert-Butyl alcohol (kg))

m = 1.121 m, mass of unknown liquid = 0.807 g, mass of tert-Butyl alcohol = 11.6 g = 0.0116 kg.

∴ molar mass of unknown liquid = (mass of unknown liquid)/(m)(mass of tert-Butyl alcohol (kg)) = (0.807 g)/(1.121 m)(0.0116 kg) = 62.06 g/mol.

ethylene glycol (molar mass = 62.07 g/mol).

explanation:

two years ago, when picking flowers in the mountains back of yosemite valley, i found a book. it was blotted and storm-beaten; all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however; many of the inner pages were well preserved. and although all were more or less stained and torn, whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today; its granite pages have been torn and blurred by the same storms that wasted the castaway book.

two years ago, when picking flowers in the mountains back of yosemite valley; i found a book. it was blotted and storm-beaten, all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however, many of the inner pages were well preserved. and although all were more or less stained and torn; whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today, its granite pages have been torn and blurred by the same storms that wasted the castaway book.