For reaction, 2NOCl _(g) $\rightleftharpoons$2NO _(g) + Cl_2 (g), K_c at 427°C is 3 × 10^-6 L mol^-1. The value of K_p is nearly

• 7.50 × 10^-5

• 2.50 × 10^-5

• 2.50 × 10^-4

• 1.75 × 10^-4

982.

For the chemical equilibrium,

CaCO_3(s) $\rightleftharpoons$CaO_(s) + CO_2(g)

$∆{\mathrm{H}}_{\mathrm{r}}^{°}$ can be determined from which one of the following plots?

• 

• 

• 

• 

pH of a solution of 10 mL 1N sodium acetate and 50 mL 2N acetic acid (K_a = 1.8 x 10^-5), is approximately :

• 4

• 5

• 6

• 7

The pH is less than 7, of the solution of :

• FeCl₃

• NaCN

• NaOH

• NaCl

Dimethyl glyoxime gives a red precipitate with Ni²⁺, which is used for its detection. To get this precipitate readily the best pH range is

• < 1

• 2-3

• 3- 4

• 9- 11

The values of K_sp for CuS, Ag₂S and HgS are 10^-31, 10⁴², 10^-54 respectively. The correct order of their solubility in water is :

• AgS > HgS > CuS

• HgS > Cus > Ag₂S

• HgS > Ag₂S > Cus

• Ag₂S > CuS > HgS

For a gaseous reaction,

C₂H₄ + H₂ $\rightleftharpoons$ C₂H₆ ; $∆$H = -32.7 Kcal.

The concentration of C₂H₄ can be decreased by :

• increasing pressure

• increasing amount of H₂

• decreasing temperature

• all of these

PCl₅ was heated in a 10 dm³ container at 250°C

PCl₅(g) $\rightleftharpoons$ PCl₃(g) + Cl₂ (g)

0.1 mol PCl₅ and 0.2 mol Cl₂ was found at equilibrium. The equilibrium constant for the reaction is :

• 0.025

• 0.04

• 0.02

• 0.05

In the reaction,

H₂SO₄ + H₂O $\rightleftharpoons$ H₃O⁺ + HSO₄^-,

the conjugate acid of water is :

• H₃O⁺

• H₂O

• HSO₄^-

• SO₄^2-

At 80°C, distilled water has H⁺ ions concentration equal to 1 x 10^-6 mole/litre. The value of K_W at this temperature will be :

• 1 X 10^-6

• 1 X 10^-12

• 1 X 10^-9

• 1 X 10^-15