At 25°C, pH of a 10^-8 M aqueous KOH solution will be

• 6.0

• 7.02

• 8.02

• 9.02

52.

In basic medium the amount of Ni²⁺ in a solution can be estimated with the dimethylglyoxime reagent. The correct statement(s) about the reaction and the product is (are) 

• in a ammoniacal solution Ni²⁺ salts give cherry-red precipitate of nickel (II) dimethylglyoximate

• two dimethylglyoximate units are bound to one Ni²⁺

• in the complex two dimethylglyoximate units are hydrogen bonded to each other

• each dimethylglyoximate unit forms a six membered chelate ring with Ni²⁺

1 x 10^-3 mole of HCl is added to a buffer solution made up of' 0.01 M acetic acid and 0.01 M sodium acetate. The final pH of the buffer (given, pK_a of acetic acid is 4.75 at 25°C)

• 4.60

• 4.66

• 4.75

• 4.8

In 'x' mL 0.3 N HCl, addition of 200 mL distilled water or addition of 100 mL 0.1 N NaOH, gives same final acid strength. Determine 'x'.

Deep blue CusO₄·5H₂O is converted to a bluish white salt at 100°C. At 250°C and 750°C it is then transformed to a white powder and black material respectively. Identify the salts.

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

• 7 - $\frac{1}{2}$pK_a - $\frac{1}{2}$log C

• $\frac{1}{2}$pK_w + $\frac{1}{2}$pK_b + $\frac{1}{2}$log C

• $\frac{1}{2}$pK_w - $\frac{1}{2}$pK_b - $\frac{1}{2}$log C

• $\frac{1}{2}$pK_w + $\frac{1}{2}$pK_a + $\frac{1}{2}$log C

If the equilibrium constants of the following equilibria,

SO₂ + $\frac{1}{2}$O₂ → SO₃ and 2SO₃ → 2SO₂ + O₂

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

• K₂ = ${\left(\frac{1}{{\mathrm{K}}_1}\right)}^2$

• K₁ = ${\left(\frac{1}{{\mathrm{K}}_2}\right)}^3$

• K₂ = $\left(\frac{1}{{\mathrm{K}}_1}\right)$

• K₂ = (K₁)²

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

• 3.74

• 4.74

• 5.74

• 6.74