Cyclohexene has a freezing point of 6.50 Degree C and a K_t of 20.0 Degree C/m,

Question

Cyclohexene has a freezing point of 6.50 Degree C and a K_t of 20.0 Degree C/m, What is the freezing point of a solution made by dissolving 0.925 g of biphenyl (C_12H_10) in 25.0 g of cyclohexene? Express the temperature numerically in degrees Celsius. Paradichlorobenzene, C_6H_4Cl_2, is a component of mothballs. A solution of 2.00 g in 22.5 g of cyclohexene boils at 82.39 Degree C. The boiling point of pure cyclohexene is 80.70 Degree C. Calculate K_b for cyclohexene. Express the constant numerically in degrees Celsius per molal

Explanation / Answer

moles C12H10 = 0.925 g /154.212 g/mol=0.00599
molality of this solution = 0.00599 mol / 0.0250 Kg =0.239

delta = m x kf = 0.239 x 20.0=4.79 °C
freezing point of this solution = 6.50 - 4.79 =1.70 °C

freezing point of this solution= 1.70 °C

b) moles C6H4Cl2 = 2.00 g/147.0 g/mol=0.0136
molality = 0.0136 mol / 0.0225 Kg =0.604
delta T = 0.604 x kb
delta T = 82.39 - 80.70=1.69
1.69 = 0.604 x kb
kb = 2.80 °C/m

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.