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

The pH of solution containing 0.10 M sodium acetate and 0.03 M acetic acid is :

(pK_a for CH₃COOH = 4.57)

• 4.09

• 6.09

• 5.09

• 7.09

The solubility of CuBr is 2 x 10^-4 mol/L at 25°C. The K_SP value for CuBr is :

• 4 x 10^-8 mol² L^-2

• 4 x 10^-4 mol² L^-2

• 4 x 10^-11 mol² L^-2

• 4 x 10^-15 mol² L^-2

Among the following the strongest acid is

• CH₃COOH

• C₆H₅COOH

• m-CH₃OC₆H₄COOH

• p-CH₃OC₆H₄COOH

Among the following the weakest base is

• C₆H₅CH₂NH₂

• C₆H₅CH₂NHCH₃

• O₂NCH₂NH₂

• CH₃NHCHO

659.

What is the pH of 0.01 M glycine solution? For glycine ${\mathrm{K}}_{\mathrm{a}1 }= 4.5 \times {10}^{-3} \mathrm{and} {\mathrm{K}}_{\mathrm{a}2 }= 1.7 \times {10}^{-10 } \mathrm{at} 298\mathrm{K}$?

• 3

• 10

• 6.1

• 7.2

In which of the following acid-base titration, pH is greater than 8 at equivalence point?

• Acetic acid versus ammonia

• Acetic acid versus sodium hydroxide

• Hydrochloric acid versus ammonia

• Hydrochloric acid versus sodium hydroxide