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? 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:

We can solve this problem using the relation:

ΔTf = (Kf)(m),

where, ΔTf is the depression in the freezing point (ΔTf = 25.5°C - 15.3°C  = 10.2 °C).

Kf is the molal freezing point depression constant of water = 9.1 °C/m,

m is the molality of the solution (m = ??? m).

∴ m = ΔTf/(Kf) = (10.2 °C)/(9.1 °C/m) = 1.12 m.

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

m = (mass/molar mass) of the solute x (1000/mass of the solvent).

∴ 1.12 m = (0.807 g / molar mass of the solute) x (1000 / 11.6 g)

∴ molar mass of the solute = (0.807 g)(1000)/(1.12 m)(11.6 g) = 62.11 g/mol.

so, the unknown liquid is ethylene glycol (molar mass = 62.07 g/mol).

explanation: it gains negative electrons, therefore becoming negatively charged. as charge cannot be created, nor destroyed, only transferred, this leaves the wool positive. now that they have opposite charges, the two items attract.