Chemistry Question Bank

Bond dissociation enthalpy of H₂ Cl₂, and HCl are 434, 242 and 431 kJ mol respectively. Enthalpy of formation of HCl is (2008)

Consider the reaction below at 298 K: C (graphite) + 2H₂ (g) → CH₄ (g) →fHº (kJ/mol) – 74.9 S₀ m(J/K/mol + 5.6 + 130.7 Which statement below is correct ?

In an isobaric process, when temperature changes from 1T to T , S is equal to

For which of the following cases H S T ?

For the gas phase reaction, 5(g) 3(g) 2(g) PCl PCl Cl Which of the following conditions are correct? (2008)

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.

Assertion: For an isolated system, q is zero. Reason: In an isolated system, change in U and V is zero.

Assertion: Addition of Q and w gives ΔU. Reason: Addition of two path functions cannot give state function.

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)

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 ,…

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)

Gaseous system is placed with pressure P₁, volume V₁ and  temperature  T1,  it  has  undergone  thermodynamic changes where temperature is remaining constant, it is

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)

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

A reaction occurs spontaneously if (2005)

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

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)

G H when S

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…

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

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)

A gas is allowed to expand in a well-insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy U of the gas in joul…

A system absorb 10 kJ of heat at constant volume and its temperature rises from 27°C to 37°C. The value of ∆U is

Which of the following is true about isolated system?