JEE Main, NEET MCQs Set 24

Sr. No.

Question

Answer

1.

Thermodynamic standard conditions of temperature and pressure are

(A) 0°C and 1 atm

(B) 273 k and 101.3 k Pa

(C) 298 k and 1 atm

(D) 0°C and 101.3 k Pa

Answer: (C)

2.

Three moles of PCl₅, three moles of PCI₃ and two moles of Clz are taken in a closed vessel. If at equilibrium the vessel has 1.5 moles of PCl₅, the number of moles of PCl₃ present in it is

(A) 5

(B) 3

(C) 6

(D) 4.5

Answer: (D)

3.

Time required for 100 percent completion of a zero order reaction is ______.

(A)

(B)

(C) a k

(D)

Answer: (D)

4.

Two gases A and B having the same volume diffuse through a porous partition in 20 and 10 seconds respectively.

The molecular mass of A is 49 u. Molecular mass of B will be

(A) 25.00 u

(B) 50.00 u

(C) 12.25 u

(D) 6.50 u

Answer: (C)

5.

Vapour pressure of pure ‘A’ is 70 mm of Hg at 25 °C. It forms an ideal solution with ‘B’ in which mole fraction of A is 0.8. lf the vapour pressure of the solution is 84 mm of Hg at 25 °C, the vapour pressure of pure ‘B’ at 25 °C is

(A) 70 mm

(B) 140 mm

(C) 28 mm

(D) 56 mm

Answer: (B)

6.

Waxes are esters of

(A) glycerol

(B) long chain alcohols

(C) glycerol and fatty acid

(D) long chain alcohols and long chain fatty acids

Answer: (D)

7.

When a sulphur sol is evaporated sulphur is obtained. On mixing with water sulphur sol

is not formed. The sol is

(A) hydrophilic

(B) hydrophobic

(C) reversible

(D) lyophilic

Answer: (B)

8.

When carbon monoxide is passed over solid caustic soda heated to 200°C, it forms

(A) Na₂CO₃

(B) NaHCO₃

(C) HCOONa

(D) CH₃COONa

Answer: (C)

9.

When compared to DG⁰ for the formation of Al₂O₃ , the AG⁰ for the formation of Cr₂O₃ is

(A) higher

(B) lower

(C) same

(D) unpredicted

Answer: (A)

10.

When conc. H₂SO₄ is heated with P₂ 0₅ , the acid is converted into

(A) sulphur

(B) sulphur dioxide

(C) sulphur trioxide

(D) a mixture of sulphur dioxide and sulphur trioxide

Answer: (C)