When a 33.8-g sample of an unknown compound is dissolved in 500. g of benzene, the freezing point of the resulting solution is 3.77°c. the freezing point of pure benzene is 5.48°c, and kf for benzene is 5.12°c/m. calculate the molar mass of the unknown compound.

The molar mass of the unknown compound is 202.40 g/mol.

Explanation:

Let the molar mass of compound be M.

The depression in freezing point is given by:

where,

= change in boiling point  = 0.81 K

=Boiling point of the solution = 3.77°C

T = freezing point of the pure solvent here benzene =5.48°C

= freezing point constant  = 5.12°C/m

m = molality =

M = 202.40 g/mol

The molar mass of the unknown compound is 202.40 g/mol.

a

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.