Use the References to access important values if needed for this question. The b

Question

Use the References to access important values if needed for this question. The boiling point of benzene, C6H6, is 80.10°C at 1 atmosphere. A nonvolatile, nonelectrolyte that dissolves in benzene is DDT A student dissolves 10.71 grams of DDT, C14HgCl5 (354.5 g/mol), in 245.6 grams of benzene. Use the table of boiling and freezing point constants to answer the questions below Kb (C/m) Kf (°C/m) Solvent Water Ethanol Chloroform Benzene Formula 1.86 0.512 1.22 3.67 2.53 Diethyl ether CH3CH2OCH2CH3 2.02 CH3CH2OH CHCl3 C616 1.99 5.12 The molality of the solution is m. The boiling point of the solution is Submit Answer Retry Entire Group 9 more group attempts remaining

Explanation / Answer

1)

Lets calculate molality first

mass(solute)= 10.71 g

use:

number of mol of solute,

n = mass of solute/molar mass of solute

=(10.71 g)/(3.545*10^2 g/mol)

= 3.021*10^-2 mol

m(solvent)= 245.6 g

= 0.2456 kg

use:

Molality,

m = number of mol / mass of solvent in Kg

=(3.021*10^-2 mol)/(0.2456 Kg)

= 0.123 molal

Answer: 0.123 molal

2)

lets now calculate Tb

Tb = Kb*m

= 2.53*0.123

= 0.3112 oC

This is increase in boiling point

boiling point of pure liquid = 80.1 oC

So, new boiling point = 80.1 + 0.3112

= 80.4112 oC

Answer: 80.4 oC

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

---

---

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