19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Which of the following reactions define o f G ? (a) diamond C O g CO g → (b) H g F g HF g → (c) H P O H O 2H PO → (d) SO g O g SO g →
H and E for the reaction, Fe O s 3H g 2Fe s H O l → at constant temperature are related as (a) H E (b) H E RT (c) H E RT (d) H E 3RT
The following data is known about the melting of a compound AB. ∆H = 9.2 kJ mol–1. ∆S = 0.008 kJ K–1mol–1. Its melting point is :
The densities of graphite and diamond at 298 K are 2.25 and 3.31 g cm–3, respectively. If the standard free energy difference is equal to 1895 J mol–1, the pressure at which graphite will be transformed into diamond a…
When 0.5 g of sulphur is burnt to SO₂ 4.6 kJ of heat is liberated. What is the enthalpy of formation of sulphurdioxide?
The heat of formation of Fe O s is –824.2 kJ mol–1. ∆H for the reaction. 2Fe O s 4Fe s 3O g → is:
H for the reaction, C(graphite) 2H (g) CH (g) → at 298 K and 1 atm is – 17900 cal. The E for the above conversion would be
The standard enthalpies of formation of HCl(g), H (g) and Cl₂(g) are –92.2, 217.7 and 121.4 kJ mol-1 respectively. The bond dissociation energy of HCl is:
A reaction occurs spontaneously if (2005)
Assume each reaction is carried out in an open container. For which reaction will H = E ? (CBSE AIPMT 2006) (a) H (g) Br (g) 2HBr(g) → (b) C(s) 2H O(g) 2H (g) CO (g) → (c) PCl (g) PCl (g) Cl (g) → (d) 2CO(g) O (g) 2CO…
The enthalpy and entropy change for the reaction: 2(l) 2(g) (g) Br Cl 2BrCl → are 30 kJ mol–1 and 105JK–1 mol–1 respectively. The temperature at which the reaction will be in equilibrium is (2006)
Consider the following reaction –1 (aq) (aq) (l) –1 2(g) 2(g) (l) 2(g) 2(g) (g) (l) –1 2(g) 2(g) 2(g) (l) –1 (i)H OH H O , H X kJ mol (ii)H 1/ 2O H O , H X kJ mol (iii)CO H CO H O , H X kJ mol (iv)C H 5 / 2O 2CO H O ,…
Bond dissociation enthalpy of H₂ Cl₂, and HCl are 434, 242 and 431 kJ mol respectively. Enthalpy of formation of HCl is (2008)
From the following bond energies: H — H bond energy : 431.37 kJ mol–1 C == C bond energy : 606.10 kJ mol–1 C — C bond energy : 336.49 kJ mol–1 C — H bond energy : 410.50 kJ mol–1 Enthalpy for the reaction, will be (2009)
The values of H and S for the reaction, (graphite) 2(g) (g) C CO 2CO → Are 170 kJ and 170 JK–1, respectively. This reaction will be spontaneous at (2009)
The heat liberated when 1.89 g of benzoic acid is burnt in a bomb calorimeter at 25 °C increases the temperature of 18.94 kg of water by 0.632 °C. If the specific heat of water at 25 °C is 0.998 cal/g-deg, the value o…
Enthalpy change for the reaction, 4H(g) 2H (g) → is – 869.6 kJ. The dissociation energy of H–H bond is (CBSE AIPMT 2011)
If the enthalpy change for the transition of liquid water to steam is 30 kJ mol–1 at 27°C, the entropy change for the process would be (2011)
Standard enthalpy of vaporisation o vap H for water at 100°C is 40.66 kJ mol–1. The internal energy of vaporisation of water at 100°C (in kJ mol–1) is (2012)
In which of the following reactions, standard reaction entropy change (∆S°) is positive and standard Gibbs energy change (∆G°) decreases sharply with increasing temperature? (2012)
When 5 litres of a gas mixture of methane and propane is perfectly combusted at 0°C and 1 atmosphere, 16 litres of oxygen at the same temperature and pressure is consumed. The amount of heat released from this combust…
For the reaction, X2O₄(l) → 2XO₂(g) ∆U = 2.1 kcal, ∆S = 20 cal K–1 at 300 K Hence, ∆G is (2014)
For a sample of perfect gas when its pressure is changed isothermally from pi to pf, the entropy change is given by. (NEET-II 2016)
Consider the following liquid-vapour equilibrium. Liquid ⇌ Vapour Which of the following relations is correct? (NEET-I 2016) (a) v H dln P dT T (b) v H d ln P dT RT (c) v H dln G dT RT (d) v H d ln P dT RT
Consider the following processes: ∆H (kJ/mol) 1/2A → B +150 3B → 2C + D –125 E + A → 2D +350 For B + D → E + 2C, ∆H will be (Mains 2011)