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.

answer: option (4) is the correct answer.

explanation:

areas which are at low altitudes and near the equator tend to receive direct sunlight from the sun. hence, heat energy or radiations from the sun make these areas warmer and they have warmest water.

whereas areas which are at high altitudes and away from the equator do no receive direct sunlight. hence, no direct contact from the sun makes these regions colder and thus, they have colder water.

thus, we can conclude that the statement areas at low latitudes near the equator have the warmest water because they receive the most direct sunlight best explains the relationship between an area's geography and the temperature of its surface water.