671.

A solution with pH = 2 is more acidic than one with a pH =6, by a factor of

• 4000

• 5000

• 8000

• 10,000

Within the list shown below, the correct pair of structures of alanine in pH ranges 2-4 and 9-11 is

I. H₃N⁺-CH(CH₃)CO₂H
II. H₂N-CH(CH₃)CO${}_2^{-}$
III. H₃N⁺-CH(CH₃)CO${}_2^{-}$
IV.H₂N-CH(CH₃)CO₂H

• I and II

• I and III

• II and III

• III and IV

Assertion: Relative strength of acids can be known by knowing the value of dissociation constant.

Reason : It gives the value of H dissolved in solution.

• If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

• If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

• If Assertion is true but Reason is false.

• If Assertion is false but Reason is true.

A 100 mL 0.1 = (M) solution of ammonium acetate is diluted by adding 100 mL of water. The pH of the resulting solution will be (pK_a of acetic acid is nearly equal to pK_b of NH₄OH).

• 4.9

• 5.0

• 7.0

• 10.0

In a reversible chemical reaction at equilibrium, if the concentration of any one of the reactants is doubled, then the equilibrium constant will:

• also be doubled

• be halved

• remains the same

• becomes one-fourth

The equivalent weight of K₂Cr₂O₇ in acidic medium is expressed in terms of its molecular weight (M) as:

• M/3

• M/4

• M/6

• M/7

20 mL 0.1 (N) acetic acid is mixed with 10 ml  0.l(N) solution of NaOH. The pH of the resulting solution is (pK_b of acetic acid is 4.74)

• 3.74

• 4.74

• 5.74

• 6.74

The pH of 10^-4M KOH solution will be

• 4

• 11

• 10.5

• 10

The pH of an aqueous solution of CH₃COONa of concentration C(M) is given by:

• 7 - 1/2 pK_a - 1/2 log C

• 1/2 pK_w + 1/2 pK_b + 1/2 log C

• 1/2 pK_w - 1/2 pK_b - 1/2 log C

• 1/2 pK_w - pK_a + 1/2 log C

If the equilibrium constants of the following equilibria,

SO₂ + 1/2O₂ $\to$ SO₃ and 2SO₃ $\to$ 2SO₂ + O₂

are given by K₁ and K₂ respectively, which of the following relations is correct?

• K₂ = (1/K₁)²

• K₁ = (1/K₃)³

• K₂ = (1/K₁)

• K₂ = (K₁)²