Gibbs energy, spontaneity and relation to equilibrium constant

37 questions on Gibbs energy, spontaneity and relation to equilibrium constant from the Thermodynamics and Thermochemistry chapter: 6 NEET level, 16 JEE Main, 15 JEE Advanced. Each one opens with its answer and solution.

• At constant temperature and pressure, a process is spontaneous when NEET level
• If the equilibrium constant K of a reaction at 298 K is greater than 1, then its standard Gibbs energy change is NEET level
• A reaction with Delta H < 0 and Delta S > 0 is NEET level
• For a reaction, Delta H deg = -112.0 kJ mol^-1 and Delta S deg = -218 J K^-1mol^-1. Calculate Delta G deg at 298 K in kJ mol^-1 (nearest integer). JEE Main level
• A reaction has Delta H deg = +55.3 kJ mol^-1 and Delta S deg = +132.0 J K^-1mol^-1 (both independent of temperature). Above what temperature, in K (nearest inte... JEE Main level
• For a reaction at 298 K, Delta G deg = -25.0 kJ mol^-1. Calculate log_10K (two decimals). Use R = 8.314 J mol^-1K^-1 and 2.303 for ln 10. JEE Main level
• The equilibrium constant of a reaction at 298 K is 1.0 x 10^-3. Using 2.303RT = 5.71 kJ mol^-1, Delta G deg is JEE Main level
• For A <=> B at 300 K, Delta G deg = +5.00 kJ mol^-1. Find Delta G in kJ mol^-1 (two decimals) when the reaction quotient is Q = 0.0100. Use R = 8.314 J mol^-1K^... JEE Main level
• A reaction releases 57.1 kJ of heat at constant temperature 298 K and constant pressure. The entropy change of the surroundings is JEE Main level
• For the vaporisation of a liquid at its normal boiling point, Delta_vapH = 38.6 kJ mol^-1 and Delta_vapS = 104 J K^-1mol^-1. The normal boiling point is about JEE Main level
• For N2(g) + 3H2(g) <=> 2NH3(g), Delta H deg < 0 and Delta S deg < 0. When the temperature is raised from 298 K to 500 K (assume Delta H deg, Delta S deg constan... JEE Main level
• For a reaction with Delta H deg = +60.0 kJ mol^-1 (independent of temperature), the equilibrium constant is K_1 at 300 K and K_2 at 330 K. Using R = 8.314 J mol... JEE Advanced level
• A reaction has Delta H deg = +30.0 kJ mol^-1 and Delta S deg = +100 J K^-1mol^-1, both independent of temperature. Select the correct statement(s). JEE Advanced level
• For N2O4(g) <=> 2NO2(g), Delta H deg = +57.2 kJ mol^-1 and Delta S deg = +175.7 J K^-1mol^-1 (take both as constant). Starting with pure N2O4 at 298 K and a tot... JEE Advanced level
• At 300 K, A -> B has Delta G deg = +20.0 kJ mol^-1 and B -> C has Delta G deg = -35.0 kJ mol^-1. The equilibrium constant of the overall reaction A -> C is abou... JEE Advanced level
• For A <=> B at 300 K, Delta G deg = +4.00 kJ mol^-1. Use R = 8.314 J mol^-1K^-1. Select the correct statement(s). JEE Advanced level
• Supercooled liquid water freezes at 263 K and 1 bar. Take Delta_fusH = 6010 J mol^-1 at 273 K (normal melting point), with Delta H and Delta S of fusion indepen... JEE Advanced level
• For CaCO3(s) <=> CaO(s) + CO2(g), take Delta H deg = +178 kJ mol^-1 and Delta S deg = +161 J K^-1mol^-1 (constant), with K_p = P_CO2/(1 bar) and R = 8.314 J mol... JEE Advanced level
• A reaction has Delta H < 0 and Delta S > 0. It is NEET level
• For a system at equilibrium at constant temperature and pressure, which statement is correct? NEET level
• If the standard Gibbs energy change of a reaction is negative, the equilibrium constant at that temperature is NEET level
• A reaction has equilibrium constant K = 1.0 x 10^3 at 298 K. Taking R = 8.314 J mol^-1K^-1, the standard Gibbs energy change is nearest to JEE Main level
• For a reaction Delta H deg = -92.0 kJ mol^-1 and Delta S deg = -199 J mol^-1K^-1, both assumed independent of temperature. Find the temperature in K above which... JEE Main level
• A reaction has Delta G deg = -11.0 kJ mol^-1 at 300 K. Taking R = 8.314 J mol^-1K^-1, find the equilibrium constant K (nearest integer). JEE Main level
• For a gaseous reaction at 298 K, Delta G deg = +5.0 kJ mol^-1. In a mixture the reaction quotient is Q = 0.010. Taking R = 8.314 J mol^-1K^-1, which statement i... JEE Main level
• For CaCO3(s) -> CaO(s) + CO2(g) take Delta H deg = +178 kJ mol^-1 and Delta S deg = +161 J mol^-1K^-1 (temperature independent). Find Delta G deg at 298 K in kJ... JEE Main level
• For a reaction Delta H deg = -40.0 kJ mol^-1 and Delta S deg = -100 J mol^-1K^-1 (temperature independent). Taking R = 8.314 J mol^-1K^-1, the equilibrium const... JEE Main level
• For melting of ice, Delta H_fus = 6010 J mol^-1 and the melting point is 273 K (assume Delta H and Delta S constant). The value of Delta G for melting at 263 K ... JEE Main level
• A gaseous reaction has K = 1.0 x 10^-2 at 298 K, so Delta G deg = +11.4 kJ mol^-1 (take R = 8.314 J mol^-1K^-1). Select all correct statements. JEE Main level
• Given Delta_fG deg(NO2) = 51.3 kJ mol^-1 and Delta_fG deg(N2O4) = 97.8 kJ mol^-1 at 298 K, consider N2O4(g) <=> 2NO2(g) (take R = 8.314 J mol^-1K^-1, standard p... JEE Advanced level
• The equilibrium constant of a reaction is 4.0 x 10^2 at 300 K and 15 at 350 K. Assuming Delta H deg and Delta S deg are constant and R = 8.314 J mol^-1K^-1, fin... JEE Advanced level
• At 310 K a reaction A -> B has Delta G deg = +30.0 kJ mol^-1 and is coupled with C -> D with Delta G deg = -50.0 kJ mol^-1. Taking R = 8.314 J mol^-1K^-1, the e... JEE Advanced level
• A reaction has Delta H deg = -60.0 kJ mol^-1 and Delta S deg = -150 J mol^-1K^-1, both independent of temperature (R = 8.314 J mol^-1K^-1). Select all correct s... JEE Advanced level
• A galvanic cell with n = 2 has E deg_cell = 0.46 V at 298 K. Using F = 96500 C mol^-1 and 2.303RT/F = 0.0591 V, the values of Delta G deg and the equilibrium co... JEE Advanced level
• For H2O(l) <=> H2O(g) at 298 K, take Delta H deg = 44.0 kJ mol^-1 and Delta S deg = 118.8 J mol^-1K^-1 (standard pressure 1 bar, 1 bar = 750 mmHg, R = 8.314 J m... JEE Advanced level
• For the gas-phase isomerisation A <=> B at 300 K, Delta G deg = -4.0 kJ mol^-1 (standard pressure 1 bar, R = 8.314 J mol^-1K^-1). Select all correct statements. JEE Advanced level
• A reaction has Delta H deg = +30.0 kJ mol^-1 and Delta S deg = +100 J mol^-1K^-1, both independent of temperature (R = 8.314 J mol^-1K^-1). Select all correct s... JEE Advanced level