Chemistry Question Bank

Consider the reaction PCl5 (g) PCl3 (g) + Cl2 (g) in a closed container at equilibrium. At a fixed temperature what will be the effect of adding more PCl5 on the equilibrium concentration of Cl2 (g) ?

The standard state Gibb’s free energy change for the isomerization reaction cis-2-pentene trans-2-pentene is –3.67 kJ mol–1 at 400 K. If more trans-2-pentene is added to the reaction vessel

For a reversible reaction : A + B C dx dt = 2.0 × 103 L mol–1 s–1 [A] [B] – 1.0 × 102 s–1 [C] where x is the amount of ‘A’ dissociated. The value of equilibrium constant (Keq) is :

A vessel at 1000 K contains CO2 with a pressure of 0.5 atm. Some of the CO2 is converted to CO on addition of graphite. If the total pressure at equilibrium is 0.8 atm, the value of K is :

The free energy of formation of NO is 78 kJ mol–1 at the temperature of an automobile engine (1000 K). What is the equilibrium constant for this reaction at 1000 K ? N (g) O (g) NO(g)

For the reaction, A B + C, at equilibrium, the concentration of A is 1 × 10–3 M, B is 0.15 and C is 0.05 M. The Gº for the hydrolysis of A at 27ºC will be :

The volume of the reaction vessel containing an equilibrium mixture is increased, while holding the temperature constant for the following reaction : SO2Cl2(g) SO2(g) + Cl2(g) When equilibrium is re-established, which…

In the equilibrium reaction AgCl(s) + 2NH3(g) 3 2 Ag(NH ) (aq) Cl (aq), an increase in the concentration of Cl –(aq) causes

Densities of diamond and graphite are 3.5 and 2.3 g/mL respectively. Increase of pressure on the equilibrium C (diamond) C (graphite)

When a liquid in equilibrium with its vapour is heated

Consider the following equilibria for gases : H2S(g) H2S(aq) + 4.6 Kcal ; SO2(g) SO2(aq) + 8.6 Kcal. Assuming the randomness factor to be about the same for each, which of the gases will have the lower solubility in…

Which of the following equilibria will shift to right side on increasing the temperature ? (PMT 2000)

The equilibrium SO2Cl2 (g) SO2 (g) + Cl2 (g) is attained at 25ºC in a closed container and an inert gas, helium is introduced. Which of the following statement is correct ? (PMT 2000)

When H2 and I2 are mixed and equilibrium is attained, then H I 2HI (PMT 2002)

If N2 + 3H2 2 NH3 – K, then 2N2 + 6H2 4NH3 – ? (PMT 2002)

The reaction quotient (Q) for the reaction N (g) 3H (g) 2NH (g) is given by [NH ] Q . [N ][H ] (CBSE Med. 2003) The reaction will proceed from right to left if

The reaction (g) (g) (g) N O 2NO is endothermic. The forward reaction is (BHU 2003)

Of the following which change will shift the reaction towards the product? (AIIMS 2004) o r I g 2I g , H 298K 150kJ

Equilibrium constant K1 and K2 for the following equilibria (AIPMT 2005) K NO(g) O NO (g) K 2NO (g) 2NO(g) O (g) are related as (a) K K (b) K K (c) K K (d) K K Ans. (d) Sol. Reaction (2) is a reverse reactio…

In the reaction, A(s) B(g) heat 2C(s) 2D(g) at equilibrium, pressure of B is doubled to re- establish the equilibrium. The factor by which concentration of D is changed, is (PMT2005) (a)

CaCO CaO CO reaction in lime kiln goes to completion because (AFMC 2005)

For the reaction r –1 CH (g) 2O (g) CO (g) 2H O( ); H 170.8 kJ mol l (CBSE AIPMT 2006) Which of the following statements is not true ?

Reaction BaO (s) BaO(s) O (g); H ve. In equilibrium condition, pressure of O depends on (PUNJAB PMET 2007)

In which of the following reactions, the concentration of the product is higher than the concentration of reactant at equilibrium? (K = equilibrium constant) (AIIMS 2008)

If the concentration of OHions in the reaction Fe OH s Fe aq 3OH aq is decreased by 4 times, the equilibrium concentration of Fe will increase by (CBSE AIPMT 2008)