Which one of the following ionic species has the greatest proton affinity to form stable compound?

(1) HS^-                         

(2) ${\mathrm{NH}}_2^{-}$

(3) F^-                           

(4) I^-

Given the reaction:

\(\mathrm{Cu}(\mathrm{~s})+2 \mathrm{Ag}^{+}(\mathrm{aq}) \rightarrow \mathrm{Cu}^{2+}(\mathrm{aq})+2 \mathrm{Ag}(\mathrm{~s})\) with E° = 0.46 V at 298 K,
what is the equilibrium constant for the reaction?

Which of the following pairs constitutes a buffer?

1. HNO₂ and NaNO₂

2. NaOH and NaCl

3. HNO₃ and NH₄NO₃

4. HCl and KCl

The hydrogen ion concentration of a 10^-8 M HCl aqueous solution at 298 K (K_w = 10^-14) is:

(1) 1.0×10^-6 M

(2) 1.0525 x 10^-7 M

(3) 9.525 x 10^-8 M

(4) 1.0×10^-8 M

For the chemical equilibrium, CaCO₃(s) $\stackrel{}{\rightleftharpoons }$ CaO(s) + CO₂ (g) ΔH_f° can be determined from which one of the following plots ?

(1)  

(2) 

(3) 

(4) 

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) $~{10}^{–10}$

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

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