Boiling point of chloroform is 61°C. After addition of 5.0 g of a non-volatile solute to 20 g chloroform boils at 64.63°C. If kb = 3.63 K kg mol^-1, what is the molecular weight of the solute?(a) 320 g/mol(b) 100 g/mol(c) 400 g/mol(d) 250 g/molThis question was posed to me during an internship interview.My question is from Colligative Properties and Determination of Molar Mass in division Solutions of Chemistry – Class 12

Boiling point of chloroform is 61°C. After addition of 5.0 g of a non

1.	Boiling point of chloroform is 61°C. After addition of 5.0 g of a non-volatile solute to 20 g chloroform boils at 64.63°C. If kb = 3.63 K kg mol^-1, what is the molecular weight of the solute?(a) 320 g/mol(b) 100 g/mol(c) 400 g/mol(d) 250 g/molThis question was posed to me during an internship interview.My question is from Colligative Properties and Determination of Molar Mass in division Solutions of Chemistry – Class 12
Answer» RIGHT answer is (d) 250 g/mol To explain: Given, b.p. of chloroform = 61°C New b.p. after ADDITION = 64.63°C Mass of solute, w2 = 5.0 g Mass of solvent, W1 = 20 g Kb = 3.63 K kg mol^-1 From these, ∆Tb = 64.63 – 61 = 3.63°C Using ΔTb = (kb x 1000 x w2)/(M2 x w1) M2 = (kb x 1000 x w2)/(ΔTb x w1) M2 = (3.63 x 1000 x 5)/(3.63 x 20) = 250 g/mol.

Discussion

No Comment Found

Related InterviewSolutions

The Van’t Hoff Factor for a solution of glucose in water is equal to 1.(a) True(b) FalseI have been asked this question during an interview.My doubt is from Abnormal Molar Masses topic in chapter Solutions of Chemistry – Class 12
117 g of NaCl is added to 222 g of water in a saucepan. At what does temperature does water boil at 101.325 kPa? Ebullioscopy constant for water = 0.52 K kg mol^-1 and b.p. = 100°C(a) 98.3°C(b) 102.8°C(c) 104.7°C(d) 101.5°CThis question was posed to me in a national level competition.My query is from Colligative Properties and Determination of Molar Mass topic in chapter Solutions of Chemistry – Class 12
Boiling point of chloroform is 61°C. After addition of 5.0 g of a non-volatile solute to 20 g chloroform boils at 64.63°C. If kb = 3.63 K kg mol^-1, what is the molecular weight of the solute?(a) 320 g/mol(b) 100 g/mol(c) 400 g/mol(d) 250 g/molThis question was posed to me during an internship interview.My question is from Colligative Properties and Determination of Molar Mass in division Solutions of Chemistry – Class 12
Why is ‘raising of viscosity’ of a solution after addition of solute, not considered to be a colligative property?(a) The resultant viscosity depends on the nature of the solute(b) The resultant viscosity depends on the amount of solute(c) The resultant viscosity depends on the nature of solvent(d) The resultant viscosity depends on the amount of solventThis question was addressed to me at a job interview.This is a very interesting question from Colligative Properties and Determination of Molar Mass in division Solutions of Chemistry – Class 12
When 2.0 grams of copper (II) nitrate is added to 1000 ml of pure water, by how much is the vapor pressure of water decreased, given that at 20°C the vapor pressure of pure water is 17.535 mm Hg?(a) 3.1 x 10^-4(b) 0.303(c) 0.0333(d) 0.0033This question was addressed to me in my homework.My doubt stems from Colligative Properties and Determination of Molar Mass in portion Solutions of Chemistry – Class 12
Which law specifically governs the relative lowering of vapor pressures in solutions?(a) van’t Hoff law(b) Boyle’s law(c) Raoult’s law(d) Amagat’s lawI had been asked this question during an online interview.I want to ask this question from Colligative Properties and Determination of Molar Mass in chapter Solutions of Chemistry – Class 12
On addition of non-volatile potassium iodide in water at 298K it is noticed that vapor pressure reduces from 23.8 mm Hg to 2.0 cm Hg. What is the mole fraction of solute in the solution?(a) 0.916(b) 0.160(c) 0.084(d) 0.092I got this question during an online exam.I would like to ask this question from Colligative Properties and Determination of Molar Mass in section Solutions of Chemistry – Class 12
Two components A and B have their pure vapor pressures in the ratio 1 ∶ 4 and respective mole fractions in solution in ratio 1 ∶ 2. What is the mole fraction of component B in vapor phase?(a) 0.8889(b) 0.1250(c) 0.8000(d) 0.2000This question was addressed to me during an internship interview.The query is from Colligative Properties and Determination of Molar Mass topic in portion Solutions of Chemistry – Class 12
Which of the following statements regarding Ideal solutions is false?(a) Ideal solutions obey Raoult’s law under all conditions of temperature and concentrations(b) There will be some change in volume on mixing the components, i.e., ΔVmixing ≠ 0(c) There will be no change in enthalpy when the two components are mixed, i.e., ΔHmixing = 0(d) There will be no change in volume on mixing the components, i.e., ΔVmixing = 0This question was addressed to me in quiz.Query is from Ideal and Non-Ideal Solutions topic in section Solutions of Chemistry – Class 12
What are the properties arising due to varying concentrations of solute in a given solvent, irrespective of the nature of solute with respect to the solvent?(a) Colligative properties(b) Intensive properties(c) Extensive properties(d) Solute propertiesThis question was addressed to me in a national level competition.My question is based upon Colligative Properties and Determination of Molar Mass in portion Solutions of Chemistry – Class 12

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment