#### 11th Standard Chemistry Solutions English Medium Free Online Test One Mark Questions with Answer Key 2020 - 2021

11th Standard

Reg.No. :
•
•
•
•
•
•

Chemistry

Time : 00:20:00 Hrs
Total Marks : 20

Answer all the questions

20 x 1 = 20
1. The partial pressure of nitrogen in air is 0.76 atm and its Henry's law constant is 7.6 × 104 atm at 300K. What is the mole fraction of nitrogen gas in the solution obtained when air is bubbled through water at 300K?

(a)

1 x 10-4

(b)

1 x 10-6

(c)

2 x 10-5

(d)

1 x 10-5

2. Which one of the following is incorrect for ideal solution?

(a)

$\Delta H_{mix}=0$

(b)

$\Delta U_{mix}=0$

(c)

$\Delta P=P_{observed}-P_{calculated\ by\ raoults\ law}=0$

(d)

$\Delta G_{mix}=0$

3. P1 and P2 are the vapour pressures of pure liquid components, 1 and 2 respectively of an ideal binary solution if x1 represents the mole fraction of component 1, the total pressure of the solution formed by 1 and 2 will be

(a)

P1 + x1 (P2 – P1)

(b)

P2 – x1 (P2 + P1)

(c)

P1 – x2 (P1 – P2)

(d)

P1 + x2 (P1 – P2)

4. 200ml of an aqueous solution of a protein contains 1.26g of protein. At 300K, the osmotic pressure of this solution is found to be 2.52 × 10–3 bar. The molar mass of protein will be (R = 0.083 L bar mol–1 K–1)

(a)

62.22 Kg mol-1

(b)

12444 g mol-1

(c)

300 g mol-1

(d)

none of these

5. Assertion: An ideal solution obeys Raoults Law
Reason: In an ideal solution, solvent-solvent, as well as solute-solute interactions, are similar to solute-solvent interactions.

(a)

both assertion and reason are true and reason is the correct explanation of assertion

(b)

both assertion and reason are true but reason is not the correct explanation of assertion

(c)

assertion is true but reason is false

(d)

both assertion and reason are false

6. Which of the following gas should have maximum value for kH?

(a)

He

(b)

H2

(c)

N2

(d)

CO2

7. In a binary solution

(a)

solvent may be liquid

(b)

solvent may be solid

(c)

solute may be gas

(d)

any of these

8. Correct statement among the following regarding osmosis is

(a)

Solvent flows from high concentration of solute to low concentration of solute

(b)

Solvent flows from low concentration of solute to high concentration of solute

(c)

Solute flows from high concentration to low concentration

(d)

Solute flows from low concentration to high concentration

9. The highest temperature at which vapour pressure of any liquid can be measured is

(a)

Critical temperature

(b)

Boyle's temperature

(c)

Boiling point of the liquid

(d)

Kraft temperature

10. Which of the following is correct about a solution showing positive deviation?

(a)

Vapour pressure observed will be the less than that calculated from Raoult's law

(b)

Minimum boiling azeotrope will be formed

(c)

$\triangle$Hmix < 0

(d)

$\triangle$Vmix < 0

11. A pressure cooker reduces cooking time for food because

(a)

Cooking involves chemical changes helped by a rise in temperature

(b)

Heat is more evenly distributed in the cooking space

(c)

Boiling point of water involved in cooking is increased

(d)

The higher pressure inside the cooker crushes the food material

12. Which of the following physical properties is used to determine, the molecular mass of a polymer solution?

(a)

Relative lowering of vapour pressure

(b)

Elevation in boiling point

(c)

Depression in freezing point

(d)

Osmotic pressure

13. The relationship between the values of osmotic pressure of 0.1 M solutions. of KNO3 (P1) and CH3COOH(P2) is

(a)

P1 > P2

(b)

P2 > P1

(c)

P1 = P2

(d)

$\frac { { P }_{ 1 } }{ { P }_{ 1 }+{ P }_{ 2 } } =\frac { { P }_{ 2 } }{ { P }_{ 1 }+2{ P }_{ 2 } }$

14. Which of the following concentration terms is temperature independent?
I) Molarity
II) Molality
III) Normality
IV) Mole fraction

(a)

I& II

(b)

I & III

(c)

II only

(d)

II & IV

15. Which one of the following is a homogeneous mixture?

(a)

Sea water

(b)

Air

(c)

Alloys

(d)

All the above

16. Statement I: The dissolution of ammonium nitrate increases steeply with increase III temperature.
Statement II: The dissolution process of ammonium nitrate is endothermic in nature.

(a)

Statement I and II are correct and statement II is the correct explanation of statement I.

(b)

Statement I and II are correct but II is not the correct explanation of I.

(c)

Statement I is correct but II is wrong

(d)

Statement I is wrong but II is correct. .

17. Which of the following is not an non-ideal solution showing negative deviation?

(a)

Phenol and aniline

(b)

Ethanol and water

(c)

Acetone + Chloroform

(d)

n-Heptane and n-Hexane

18. Statement I: Acetic acid deviates from ideal behaviour.
Statement II: Acetic acid exists as a dimer by forming inter molecular hydrogen bonds and hence deviates from Raoult's law.

(a)

Statement I& II are correct and II is the correct explanation of I.

(b)

Statement I& II are correct but II is not the correct explanation of I.

(c)

Statement I is true but II is wrong.

(d)

Statement I is wrong but II is correct.

19. What would be the value of van't Hoff factor for a dilute solution of K2SO4 in water

(a)

3

(b)

2

(c)

1

(d)

4

20. Which of the following is not a colligative property?

(a)

optical activity

(b)

osmotic pressure

(c)

elevation boiling point

(d)

depression in freezing point