Chemistry Question Bank

Given that bond energies of H – H and Cl – Cl are 430 kJ mol–1 and 240 kJ mol–1 respectively and f H for HCl is-90 kJ mol–1 bond enthalpy of HCl is (2007)

For the gas phase reaction, 5(g) 3(g) 2(g) PCl PCl Cl Which of the following conditions are correct? (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)

Identify the correct statement for change of Gibbs’ energy for a system system ( G ) at constant temperature and pressure. (2006)

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 ,…

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…

Which of the following are not state functins? (I) q + w (II) Q (III) w (IV) H – TS (2009)

The densities of graphite and diamond at 298 K are 2.25 and 3.31 g cm–3, respectively. The standard free energy difference ( G ) is equal to 1895 J mol–1, the pressure at which graphite will be transformed into diamon…

The absolute enthalpy of neutralisation of the reaction: (g) (g) 2(aq) (l) MgO 2HCl MgCl H O → Will be (2005)

If the bond energies of H–H, Br–Br, and H–Br are 433, 192 and 364 kJ mol–1 respectively, the H for the reaction 2(g) 2(g) (g) H Br 2HBr → is (2004)

The heat of combustion of carbon to CO₂ is –393.5 kJ/mol. The heat released upon formation of 35.2 g of CO₂ from carbon and oxygen gas is (2015)

A reaction occurs spontaneously if (2005)

The molar heat capacity of water at constant pressure, C, is 75J K-1. When 1.0 kJ of heat is supplied to 100 g of water which is free to expand, the increase in temperature of water is. (2003)

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)

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:

105. (∆U – ∆H) for the formation of NH₃ from N₂ and H₂ 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

∆H for the reaction, SO g O g SO g ∆H = –98.3 kJ If the enthalpy of formation of SO₃(g) is –395.4 kJ then the enthalpy of formation of SO₂(g) 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…

For the reaction, 2H O g 2H g O g → ∆H = 571.6 KJ fH of water is :

Assertion: There is no change in internal energy for an ideal gas at constant temperature. Reason: Internal energy of an ideal gas is a function of temperature only.

The enthalpy of vaporisation of a compound AB at its boiling point (127°C) is 6.4 kJ mol-1. Its entropy of vaporization is

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 :