In the Haber process for the industrial manufacture of ammonia involving the reaction, N₂ + 3H₂ $\stackrel{}{\rightleftharpoons }$ 2NH₃ at 200 atm pressure in the presence of a catalyst, temperature of about 500°C. This is considered as optimum temperature for the process because

(1) yield is maximum at this temperature

(2) catalyst is active only at this temperature

(3) energy needed for the reaction is easily obtained at this temperature

(4) rate of the catalytic reaction is fast enough while the yield is also appreciable for this exothermic reaction at this temperature.

For the equilibrium of the reaction,\(\mathrm{HgO}(\mathrm{~s}) \rightleftharpoons \mathrm{Hg}(\mathrm{~g})+\frac{1}{2} \mathrm{O}_ 2(\mathrm{~g}), \mathrm{K_P}\) for the reaction at a total pressure of "P" will be:

The pH of glycine at the first half equivalence point is 2.34 and that at second half equivalence point is 9.60.At the equivalence point (The first inflection point) The pH is :

(1) 3.63

(2) 2.34

(3) 5.97

(4) 11.94

30 ml of 0.06 M solution of the protonated form of an anion acid methionine (H₂A⁺) is treated with 0.09 M NaOH. Calculate pH after addition of 20 ml of base.[ pKa₁, = 2.28 and pKa₂ = 9.2.]

1. 5.5

2. 5.74

3. 9.5

4. None of the above

A certain acid–base indicator is red in acid solution and blue in basic solution 75% of the indicator is presentin the solution in its blue form at pH = 5. Calculate the pH at which the indicator shows 90% red form?

(1) 3.56

(2) 5.47

(3) 2.5

(4) 7.4

Ionisation constant of HA (weak acid) and BOH (weak base) are 3.0 x 10^–7 each at 298K. The percent degree of hydrolysis of BA at the dilution of 10L is :

1. 25

2. 50

3. 75

4. 40

Calculate the molar solubility of zinc tetrathiocyanato–N–mercurate (II) if its K_sp = 2.2 x 10^–7.

(1) 0.00380

(2) 0.000469

(3) 0.0095

(4) 0.0183

A buffer solution is made by mixing a weak acid HA (K_a = 10^–6) with its salt NaA in equal amounts. What should be the amount of acid or salt that should be added to make 90 ml of buffer solution of buffer capacity. 0.1 ?

(1) 10 milli moles

(2) 22 milli moles

(3) 9 milli moles

(4) 11 milli moles

The reactions, PCl₅ (g) $\stackrel{}{\rightleftharpoons }$ PCl₃(g) + Cl₂(g) and COCl₂(g) $\stackrel{}{\rightleftharpoons }$ CO(g) + Cl₂(g) are simultaneously in equilibrium in an equilibrium box at constant volume. A few moles of CO(g) are later introduced into the vessel. After some time, the new equilibrium concentration of

(1) PCl₅ will remain unchanged

(2) Cl₂ will be greater

(3) PCl₅ will become less

(4) PCl₅ will become greater

Equilibrium constant for the given reaction is kc = 10²⁰ at temperature 300 K,A(s) + 2B (aq.) $\stackrel{}{\rightleftharpoons }$ 2C (s) + D (aq.)K = 10²⁰ The equilibrium conc. of B starting with mixture of 1 mole of A and 1/3 mole/litre of B at 300 K is

(1) $~4\times {10}^{–11}$

(2) $~2\times {10}^{–10}$

(3) $~2\times {10}^{–11}$

(4) $~{10}^{–10}$