JEE Main, NEET MCQs Set 30


JEE MAIN, AIPMT, Chemistry Question Papers – MCQs Test 30

Sr. No.

Question

Answer

1. Following is the substitution reaction in which —CN replaces —ClR – Cl + R – CN + KClTo obtain propanenitrile, R-Cl should be

(A) 1- chloropropane

(B) chloroethane

(C) 2-chloropropane

(D) chloromethane

Answer: (B)
2. For a chemical reaction of the typeA ⇄ B, K = 2.0 and B ⇄ C, K = 0.01Equilibrium constant for the reaction 2C ⇌ 2A is

(A) 25

(B) 50

(C) 2500

(D) 4 × 10–4

Answer: (C)
3. For a reaction A + B → C + D if the concentration of A is doubled without altering the concentration of B, the rate gets doubled. lf the concentration of B is increased by nine times without altering the concentration of A, the rate gets tripled. The order of the reaction is

(A) 2

(B) 1

(C)

(D)

Answer: (C)
4. For a reaction to be spontaneous at all temperatures(A) ΔG and ΔH should be negative

(B) ΔG and ΔH should be positive

(C) ΔG = ΔS = 0

(D) ΔH < ΔG

Answer: (A)
5. For a reversible reaction : X(g) + 3Y(g) ⇌ 2Z(g)DH = –40 kJ the standard entropies of X, Y and Z arc 60, 40 and 50 JKmol1 respectively.The temperature at which the above reaction attains equilibrium is about

(A) 400 K

(B) 500 K

(C) 273 K

(D) 373 K

Answer: (B)
6. For preparing a buffer solution of pH = 7.0, which buffer system you will choose?

(A) H3 PO4, H2

(B) H2 ,

(C),

(D)H3 PO4,

Answer: (B)
7. For the following reaction C6H12O6(aq) + H2(g) ⇌ C6H14O6(aq)Which one of the following is not affected by the addition of catalyst?

(A) Rate of forward reaction

(B) Rate of backward reaction

(C) Time required to reach the equilibrium

(D) Spontaneity

Answer: (D)
8.

For the given alkane

The IUPAC name is

(A) 1, 1 dimethyl-5-ethyl octane

(B) 6-ethyl-2-methyl nonane

(C) 4-ethyl-8-methyl nonane

(D) 2-methyl, -6-propyl octane

Answer: (B)
9. For the reactionsI2(aq) ⇌ I2(oil) Equilibrium constant is K1I2(oil) ⇌  I2(ether) Equilibrium constant is K2 for the reaction

I2(aq) ⇌ I2(ether) Equilibrium constant is K3

The relation between K1, K2, K3 is

(A) K3 = K1 + K2

(B) K3 = K1K2

(C) K3 = K1/K2

(D) K3 = K2/K1

Answer: (B)
10. For the reversible reaction,
A(s) + B(g) ⇌ C(g) + D(g) ΔG° = –350 kJ,
which one of the following statements is true?(A) The entropy change is negative

(B) The reaction is thermodynamically nonfeasible

(C) The reaction should be instantaneous

(D) Equilibrium constant is greater then one.

Answer: (D)
11. For transition metal octahedral complexes, the choice between high spin and low spin electronic configurations arises only for(A) d1 to d3 complexes

(B) d4 to d7 complexes

(C) d7 to d9 complexes

(D) d1, d2 and d8 complexes

Answer: (B)
12. Formic acid is a stronger acid than acetic acid. This can be explained using(A) –I effect

(B) +M effect

(C) –M effect

(D) +I effect

Answer: (D)
13. Generally, the first ionization energy increases along a period. But there are some exceptions. The one which is NOT an exception is ______.(A) Be and B

(B) Na and Mg

(C) Mg and Al

(D) N and O

Answer: (B)
14. Given a gas phase reaction
2A(g) + B(g) ⇌ C(g) + D(g)Which one of the following changes will affect the value of KC?

(A) Addition of inert gas

(B) Addition of catalyst

(C) Addition of reactants

(D) Increasing in temperature

Answer: (D)
15. Given exothermic reaction (aq) + 6H2O(1) ⇌ [Co(H2O)]2+ +4CIWhich one of the following will decrease the equilibrium concentration of ?(A) Addition of HCI

(B) Addition of Co(NO3)2

(C) The solution is diluted with water

(D) The temperature is increased

Answer: (C)

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