Calculate the molar mass of a compound if a solution of 12.0 g dissolved in 80.0 g of water freezes at −1.94 °C. Kf (freezing point depression constant for water) = 1.86 oC/m; FP (freezing point of water) = 0oC; density of water 1 g/mL

Molar mass = 144.2 g/mol

Explanation:

Formula to solve this: ΔT = Kf . m

ΔT → Freezing point of pure solvent - Freezing point of solution

0°C - (-1.94°C) = 1.86 °C/m . m

1.94°C / 1.86 m/°C = m →  1.04 m

1.04 are the moles of solute in 1kg of solvent → molality (mol/kg)

Let's convert the mass of our solvent in kg to determine the moles.

80 g . 1kg / 1000 g = 0.08 kg

Molality . kg of solvent → Solute moles

1.04 mol/kg . 0.080 kg = 0.0832 moles

These are the moles of 12 g of solute. To find the molar mass → g/mol

12 g / 0.0832 mol = 144.2 g/mol

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.