For the reaction: H_{2 (g)} + I_{2 (g)}  $\rightleftharpoons \hspace{0.17em}$2HI _(g) ; K_c = 54.8 at 700K .

If 0.5 mol L^–1 of HI_(g) is present at equilibrium at 700 K, the concentration of H_2(g) and I_2(g)  would be:

1. [H₂]= [I₂]=0.05 mol L^-1

2. [H₂]= 0.5 mol L^-1, [I₂] = 0.05 mol L^-1

3. [H₂] = 0.068 mol L^-1, [I₂]= 0.55 mol L^-1

4. [H₂] = [I₂] =0.068 mol L^-1

What will be the equilibrium concentration of ICl when its initial concentration is 0.78 M for the reaction:
2ICl_(g) $\leftrightharpoons \hspace{0.17em}$I_2(g) + Cl_2(g); K_c = 0.14 ?

Given the reaction:
CH₃COOH_(l) + C₂H₅OH_(l) ⇌ CH₃COOC₂H_5(l) + H₂O_(l)

At 293 K, a mixture is prepared starting with 1.00 mol of acetic acid and 0.18 mol of ethanol.
At equilibrium, 0.171 mol of ethyl acetate is formed.
Calculate the equilibrium constant (Kc) for the reaction.

(a) PCl_{5 (g)} $\leftrightharpoons$ PCl_{3 (g)} + Cl_{2 (g)}

(b) CaO _(s) + CO_{2 (g)} $\leftrightharpoons$  CaCO_{3 (s)}

(c) 3Fe _(s) + 4H₂O _(g) $\leftrightharpoons$ Fe₃O_{4 (s)} + 4H_{2 (g)}

The effect of an increase in the volume on the number of moles of products in the above-mentioned reactions would be, respectively:

1. a) Increase,  b) decrease, c) same

2. a) Decrease,  b) same, c) increase

3. a) Increase,  b) increase, c) same

4. a) Increase,  b) decrease, c) increase

Consider the following reactions:

(i) COCl_{2 (g)}  $\leftrightharpoons \hspace{0.17em}$CO _(g) + Cl_{2 (g)}

(ii) CO_{2 (g)} + C _(s) $\leftrightharpoons$ 2CO _(g)

(iii) 2H_{2 (g)} + CO _(g) $\leftrightharpoons$ CH₃OH _(g)

1. Only (iii)

2. Only (ii)

3. Both (i) and (ii) 

4. None of the above.

Given an endothermic reaction:

CH_{4 (g)} + H₂O _(g)  $\leftrightharpoons \hspace{0.17em}$CO _(g) + 3H_{2 (g)}

If the temperature is increased, then:

1. The equilibrium will not be disturbed.

2. The equilibrium will shift in the backward direction.

3. The equilibrium will shift in the forward direction.

4. None of the above.

Find the effect of (i) increasing pressure and (ii) increasing temperature on Kc for the following equilibrium:

PCl₅(g) ⇌ PCl₃(g) + Cl₂(g)

ΔᵣH° = +124.0 kJ mol⁻¹
Kc = 8.3 × 10⁻³ mol L⁻¹ at 473 K

The conjugate acid-base pair is:

1. A pair that differs only by one proton

2. A pair that differs only by the size

3. A pair that differs only by electronegativity

4. None of the above

The conjugate acids for the Brönsted bases  ${\mathrm{NH}}_2^{-}$ , NH₃ and HCOO^– will be respectively:

1. N₂H₆, ${\mathrm{NH}}_4^{+}$ HCOOH

2. NH₃, ${\mathrm{NH}}_4^{+}$ , HCOOH

3. NH₃, ${\mathrm{NH}}_4^{+}$, HCOO₃

4. N₂H, ${\mathrm{NH}}_4^{+}$, HCOOH