For the reaction N₂O₄(g) ⇌ 2NO₂(g), the value of K(equilibrium constant) is 50 at 400 K and 1700 at 500 K. Which of the following option(s) is/are correct?

(a)	The reaction is endothermic.
(b)	The reaction is exothermic.
(c)	If NO2(g) and N2O4(g) are mixed at 400 K at partial pressures 20 bar and 2 bar respectively, more N2O4(g)  will be formed.
(d)	The entropy of the system increases.

1. (a, b, d)

2. (b, c, d)

3. (b, d, a)

4. (a, c, d)

What is the term used to define the temperature at which the solid and liquid phases of a pure substance can exist in equilibrium at a particular temperature and atmospheric pressure?

(a) Normal melting point

(b) Equilibrium temperature

(c) Boiling point

(d) Freezing point

Choose the correct option:

Which of the following acids forms three series of salts?

The correct decreasing order of basic strength of the following species is.

${\mathrm{H}}_2\mathrm{O},{\mathrm{NH}}_3,{\mathrm{OH}}^{-},{\mathrm{NH}}_2^{}$

$1.<mspace\; width="1em"></mspace>{\mathrm{NH}}_2^{-}>{\mathrm{OH}}^{-}>{\mathrm{NH}}_3>{\mathrm{H}}_2\mathrm{O}$
$2.<mspace\; width="1em"></mspace>{\mathrm{OH}}^{-}>{\mathrm{NH}}_2^{-}>{\mathrm{H}}_2\mathrm{O}>{\mathrm{NH}}_3$
$3.<mspace\; width="1em"></mspace>{\mathrm{NH}}_3>{\mathrm{H}}_2\mathrm{O}>{\mathrm{NH}}_2^{-}>{\mathrm{OH}}^{-}$
$4.<mspace\; width="1em"></mspace>{\mathrm{H}}_2\mathrm{O}>{\mathrm{NH}}_3>{\mathrm{OH}}^{-}>{\mathrm{NH}}_2^{-}$

Find the equilibrium constant (K_c) at 500 K for:

2HI(g) ⇌ H₂(g) + I₂(g)

given that:

½H₂(g) + ½I₂(g) ⇌ HI(g), K_c = 5
 

1.  0.04

2.  0.4

3.  25

4.  2.5

On increasing the pressure, the direction in which the gas phase reaction proceeds to re-establish equilibrium is predicted by applying Le-Chatelier's principle. Consider the reaction,

${\mathrm{N}}_2\left(\mathrm{g}\right)+3{\mathrm{H}}_2\left(\mathrm{g}\right)\rightleftharpoons 2{\mathrm{NH}}_3\left(\mathrm{g}\right)$

Which of the following is correct, if the total pressure at which the equilibrium is established is increased without changing the temperature?

Which of the following alternatives best describes the reaction A ⇌ B at its halfway point?
1. \(\Delta G^{\ominus}=0\)
2. \(\Delta G^{\ominus}>0\)
3. \(\Delta G^{\ominus}<0\)
4. \(\Delta G^{\ominus}=-RTlnK\)

${\mathrm{}}_{}$
Find the pH of ammonium acetate solution when the value of Ka for CH₃COOH is 1.8 × 10⁻⁵
and Kb for NH₄OH is 1.8 × 10⁻⁵.

1. 7.005

2. 4.75

3. 7.0

4. Between 6 and 7

The value of the pH of \(0.01 \) \(\text{mol dm}^{-3}   \)\(\text{CH}_3\text{COOH}\) \(\left(K_a=1.74 \times 10^{-5}\right)\)  is: