SOLUTIONS Quiz-8

Solutions Quiz-8

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IIT JEE exam which consists of JEE Main and JEE Advanced is one of the most important entrance exams for engineering aspirants. The exam is held for candidates who are aspiring to pursue a career in the field of engineering and technical studies. Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything..

Q1. The freezing point of a solution prepared from 1.25 g of non-electrolyte and 20 g of water is 271.9K. If the molar depression constant is 1.86 K mol^(-1), then molar mass of the solute will be

•  105.7
•  106.7
•  115.3
•  93.9

Solution

Q2.The mole fraction of component A in vapour phase is χ₁ and mole fraction of component A in liquid mixture is χ₂ (P_A° = vapour pressure of pure A; P_B° = vapour pressure of pure B). Then total vapour pressure of the liquid mixture is

•  (P_A °χ₂)/χ₁
•  (P_A °χ₁)/χ₂
•  (P_A °χ₁)/χ₂
•  (P_B °χ₂)/χ₁

Q3.  Dissolving 120 g of urea (mol. Wt. 60) in1000 g of water gave a solution of density 1.15 g/mL. The molarity of the solution is

•  1.78M
•  2.00M
•  2.05M
•  2.22M

Solution

Q4. Which of the following solutions has the minimum freezing point

•  1 molal NaCl solution
•  1 molal KCl solution
•  1 molal CaCl₂ solution
•  1 molal urea solution

Solution

Q5.If P° and P_s are vapour pressures of solvent and its solution, respectively, χ₁ and χ₂ are mole fractions of solvent and solute, respectively, then

•  P_s=P°/χ₂
•  P⁰-P_s=P°χ₂
•  P_s=P°χ₂
•  (P°-P_s)/P_s =(χ₁ )/(χ₁+ χ₂ )

Solution

Q6. When mercuric iodide is added to the aqueous solution of potassium iodide,

•  Freezing point is raised
•  Freezing point is lowered
• Freezing point does not change
•  Boiling point does not change

Solution

Q7.The vapour pressure of a solvent decreased by 10 mm of Hg when a non-volatile solute was added to the solvent. The mole fraction of solute in solution is 0.2, what would be the mole fraction of solvent if the decrease in vapour pressure is 20 mm of Hg

•  0.8
•  0.6
•  0.4
•  0.2

Solution

Q8.Which of the following solutions has the maximum freezing point?

•  1 molar of NaCl solution
•  1 molar of KCl solution
•  1 molar of CaCl₂ solution
•  1 molar of urea solution

Solution

Q9.If Raoult's law is obeyed, the vapour pressure of the solvent in a solution is directly proportional to

•  The mole fraction of the solvent
•  The mole fraction of the solute
•  The mole fraction of the solvent and solute
•  The volume of the solution

Solution

Q10. The vapour pressure of pure benzene C₆ H₆ at 50℃ is 268 torr. How many moles of non-volatile solute per mole of benzene is required to prepare a solution of benzene having a vapour pressure of 167 torr at 50℃?

•  0.377
•  0.605
•  0.623
• 0.395

Solution

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