Asolution of 2.00 g of para-dichlorobenzene in 50.0 g
ofcyclohexane freezes at 1.05oc. what is the molarmass
of this substance?

151 g/mol

Explanation:

When a nonvolatile substance is added to a solvent, the freezing point of the solvent is changed, which is called cryoscopy. When temperature change can be calculated by:

ΔT = Kf*W

Where Kf is the molal freezing point constant of the solvent and W is the molality of the solution.

For cyclohexane, Kf = 20.2 °C/molal, and the freezing point is 6.4 °C, so:

6.4 - 1.05 = 20.2 * W

20.2W = 5.35

W = 0.26485 molal

The molality is:

W = m1/m2*M1

Where m1 is the mass of the solute (in g), m2 is the mass of the solvent (in kg), and M1 is the molar mass of the solute. So:

0.26485 = 2.00/0.05M1

0.0132425M1 = 2.00

M1 = 151 g/mol

the answers would be

the first one and the second one

b. accuracy of the data matters alot more than its number of digits, organization or amount of detail. quantitative observation is more accepted than the qualitative observation.