Reaction quotient and direction of reaction

28 questions on Reaction quotient and direction of reaction from the Chemical Equilibrium chapter: 6 NEET level, 11 JEE Main, 11 JEE Advanced. Each one opens with its answer and solution.

• For H2(g) + I2(g) <=> 2HI(g) the equilibrium constant is K_c = 50 at a given temperature. A mixture has [H2] = 0.20 mol L^-1, [I2] = 0.10 mol L^-1 and [HI] = 0.... NEET level
• For a reversible reaction at constant temperature the reaction quotient is found to be greater than the equilibrium constant (Q > K). Which statement is correct... NEET level
• For CaCO3(s) <=> CaO(s) + CO2(g), K_p = 0.5 atm at a certain temperature. A closed vessel containing solid CaCO3 and solid CaO has p_CO2 = 0.2 atm. What happens... NEET level
• For 2SO2(g) + O2(g) <=> 2SO3(g), K_c = 100 L mol^-1 at some temperature. A mixture has [SO2] = 0.10, [O2] = 0.20 and [SO3] = 0.50 (all in mol L^-1). The reactio... NEET level
• A reaction mixture has reached equilibrium at constant temperature. Which of the following is necessarily true? NEET level
• The correct expression of the reaction quotient for N2(g) + 3H2(g) <=> 2NH3(g) in terms of concentrations is NEET level
• For PCl5(g) <=> PCl3(g) + Cl2(g), K_c = 0.04 mol L^-1 at a certain temperature. A 5.0 L vessel contains 0.50 mol PCl5, 0.30 mol PCl3 and 0.40 mol Cl2. Choose th... JEE Main level
• For N2O4(g) <=> 2NO2(g), K_p = 3.0 atm at a given temperature. A gas mixture containing 1.0 mol N2O4 and 3.0 mol NO2 is held at a total pressure of 2.0 atm at t... JEE Main level
• The reaction N2O4(g) <=> 2NO2(g) is at equilibrium in a cylinder at constant temperature. The volume is suddenly halved. Immediately afterwards, the reaction qu... JEE Main level
• N2(g) + 3H2(g) <=> 2NH3(g) is at equilibrium in a cylinder with a movable piston. Argon is added at constant temperature and constant total pressure (so the vol... JEE Main level
• For 2SO2(g) + O2(g) <=> 2SO3(g), K_c = 400 L mol^-1 at a given temperature. For SO3(g) <=> SO2(g) + 1/2 O2(g) at the same temperature, K_c in mol^1/2 L^-1/2 is JEE Main level
• For CH3COOH + C2H5OH <=> CH3COOC2H5 + H2O in solution, K_c = 4.0. A mixture has [CH3COOH] = 0.20, [CH3COOC2H5] = 0.30 and [H2O] = 0.45 (all in mol L^-1). The ne... JEE Main level
• For N2O4(g) <=> 2NO2(g), K_p = 0.14 atm at a given temperature. In a vessel p_N2O4 = 0.75 atm. The reaction goes backward (dimerisation) only if p_NO2 exceeds a... JEE Main level
• For N2(g) + 3H2(g) <=> 2NH3(g), K_c = 60 L^2 mol^-2 at 500 K. A gas mixture at this temperature has partial pressures p_N2 = 4.0, p_H2 = 6.0 and p_NH3 = 2.0 atm... JEE Main level
• For H2(g) + I2(g) <=> 2HI(g), K_c = 45 at a certain temperature. A 2.0 L vessel holds 1.0 mol H2 and 1.0 mol I2. How many moles of HI must also be present for t... JEE Main level
• A reaction mixture at constant temperature has Q = 0.8K. Which of the following statements are correct? JEE Main level
• N2(g) + 3H2(g) <=> 2NH3(g) is at equilibrium at constant temperature. Which of the following changes make Q_c > K_c immediately after the change? JEE Main level
• A 2.0 L vessel contains an equilibrium mixture of 0.080 mol N2O4 and 0.040 mol NO2 for N2O4(g) <=> 2NO2(g) at fixed temperature. Then 0.060 mol of NO2 is inject... JEE Advanced level
• For C(s) + CO2(g) <=> 2CO(g), K_p = 1.9 atm at 1000 K. Excess graphite is in contact with a gas mixture containing 2.0 mol CO and 1.0 mol CO2 at a total pressur... JEE Advanced level
• For N2(g) + 3H2(g) <=> 2NH3(g), K_c = 0.50 L^2 mol^-2 at 400 K. Use R = 0.0821 L atm mol^-1 K^-1. A mixture at 400 K has partial pressures p_N2 = 2.0, p_H2 = 6.... JEE Advanced level
• Two coupled gas-phase isomerisations occur at constant volume and temperature: A <=> B with K_1 = 4.0, and B <=> C with K_2 = 0.50. The mixture has [A] = 0.50, ... JEE Advanced level
• Two different equilibrium mixtures of the same reaction A(g) <=> 2B(g) at the same temperature are prepared in two vessels of equal volume: mixture 1 has [A] = ... JEE Advanced level
• For C(s) + CO2(g) <=> 2CO(g), K_p = 2.0 atm at a fixed temperature. A gas mixture over excess graphite always has the mole ratio n_CO : n_CO2 = 3 : 1. At what t... JEE Advanced level
• A 3.0 L flask holds 0.30 mol NO2 and a 2.0 L flask holds 0.10 mol N2O4, at the same temperature. For N2O4(g) <=> 2NO2(g), K_c = 0.0065 mol L^-1 at this temperat... JEE Advanced level
• For CaCO3(s) <=> CaO(s) + CO2(g), K_p = 0.80 atm at 1100 K. A rigid 5.0 L vessel at 1100 K contains solid CaCO3 and CaO together with some CO2 (ideal gas). The ... JEE Advanced level
• For PCl5(g) <=> PCl3(g) + Cl2(g) an equilibrium mixture in a 10.0 L vessel contains 0.40 mol PCl5, 0.20 mol PCl3 and 0.20 mol Cl2. At constant temperature the v... JEE Advanced level
• For A(g) + B(g) <=> C(g), K_c = 10 L mol^-1 at a given temperature. Four mixtures are prepared (concentrations in mol L^-1). For which of them does the net reac... JEE Advanced level
• Which of the following reaction quotients are written correctly (pure solids and liquids omitted, activity of species in solution taken as concentration in mol ... JEE Advanced level