The answer to the problem is
69.55
Answer: 3.306 mmol
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.
where,
Molarity
n= moles of solute
= volume of solution in ml
According to stoichiometry:
1 mole of 
gives 2 moles of 
1.653 mmol of gives =
of
Thus number of millimoles of are 3.306
Answer:
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
