What is the amount of work done when 0.5 mole of methane, CH₄(g), is subjected to combustion at 300 K? (Given, R=8.314JK^-1 mol^-1)

• -2494 J

• -4988 J

• + 4988 J

• + 2494 J

In the reaction; A₂(g) + 3B₂(g) → 2AB₃(g), the standard entropies in (JK^-1 mol^-1) of A₂(g), B₂(g) and AB₃(g) are respectively 190, 130 and 195 and the standard enthalpy change for the reaction is -95 kJ mol^-1. The temperature (in K) at which the reaction attains equilibrium is (assuming both the standard entropy change and standard enthalpy change for this reaction are constant over a wide range of temperature)

• 500

• 400

• 300

• 200

Calculate the standard enthalpy change (in kJ mol^-1) for the reaction

    H₂(g) + O₂(g) → H₂O₂(g)

Given that bond enthalpies of H-H, O=O, O-H and O-O (in KJ mol^-1) are respectively 438, 498, 464 and 138.

• -130

• -65

• +130

• -334

According to the first law of thermodynamics which of the following quantities represents the change in a state function?

• q_rev + W_rev

• q_rev

• q_rev - W_rev

• q_rev / W_rev

105.

If the activation energy for the forward reaction is 150 kJ mol^-1 and that of the reverse reaction is 260 kJ mol^-1, what is the enthalpy change for the reaction?

• 410 kJ mol^-1

• 110kJ mol^-1

• -110 kJ mol^-1

• -410 kJ mol^-1

When 0.2 g of 1-butanol was burnt in a suitable apparatus, the heat evolved was sufficient to raise the temperature of 200 g water by 5°C. The enthalpy of combustion of 1-butanol in kcal mol^-1 will be

• +37

• +370

• -370

• -740

Given that dE = Tds - pdV and H = E + pV. Which one of the following relations is true ?

• dH = TdS + Vdp

• dH = SdT + Vdp

• dH = -SdT + Vdp

• dH = dE + pdV

Using the following thermochemical equations

(i) S(rh) + 3/2O₂(g) → SO₃ (g)       ΔH = -2x kJ mol^-1

(ii) SO₂(g) + 1/2O₂ (g)  → SO₃ (g)  ΔH = -y kJ mol^-1

Find out the heat of formation of SO₂ (g) in kJ mol^-1.

• (2x + y)

• (x + y)

• (2x/y)

• (y- 2x)

The activation energy of exothermic reaction A → B is 80 kJ mo1^-1. The heat of reaction is 200 kJ mol^-1. The activation evergy for the reaction B → A (in kJ mol^-1) will be

• 280

• 200

• 120

• 40

What would be the heat released when an aqueous solution containing 0.5 mole of HNO₃ is mixed with 0.3 mole of OH^- (enthalpy of neutralization is -57.1 k.J) ?

• 28.5 kJ

• 17.1 kJ

• 45.7 kJ

• 1.7 kJ