Find the enthalpy of formation of FeS when 2.1 g of Fe combines completely with sulfur and releases 3.77 kJ of heat.

1.	– 3.77	2.	– 1.79
3.	– 100.5	4.	None of the above

Pairs correctly represent intensive property among the following is:

1. Entropy, Gibb’s energy

2. Enthalpy, Heat capacity

3. Electrode potential, Vapour pressure

4. Resistance, Conductance

An ideal gas is expanded irreversibly against 10 bar pressure from 20 litres to 30 litres. Calculate 'w' if the process is isoenthalpic.

The standard enthalpy of combustion at ${25}^{\circ }C$ of hydrogen, cyclohexene (C₆H₁₀), and cyclohexane (C₆H₁₂) are -241, -3800 and -3920 kJ mol^-1, respectively. Calculate the standard enthalpy of hydrogenation of cyclohexene.

Consider the following reaction,

S + O₂ $\to$ SO₂,  $∆$H = – 298.2 kJ mole^–1

SO₂ + 1/2 O₂ $\to$  SO₃, $∆$H = – 98.7kJ mole^–1

SO₃ + H₂O $\to$ H₂SO₄ , $∆$H = – 130.2 kJ mole^–1

H₂ + 1/2 O₂ $\to$ H₂O, $∆$H = – 287.3 kJ mole^–1

the enthalpy of formation of H₂SO₄ at 298 K will be:

On complete combustion, 4.8 g of diamond releases 158.4 kJ of heat. The standard enthalpy of formation of gaseous carbon is 725 kJ mol⁻¹. Calculate the energy required for the following process:
(Given - Heat of combustion of graphite is −394 kJ mol⁻¹.)

(i) $\mathrm{C}\left(\mathrm{graphite}\right)\to \mathrm{C}\left(\mathrm{gas}\right)$

(ii) $\mathrm{C}\left(\mathrm{diamond}\right)\to \mathrm{C}\left(\mathrm{gas}\right)$

As an isolated box, equally partitioned, contains two ideal gasses A and B as shown:

When the partition is removed, the gases mix. The changes in enthalpy $(∆\mathrm{H})$ and entropy $(∆\mathrm{S})$ in the process, respectively, are

1. Zero, positive

2. Zero, negative

3. Positive, zero

4. Negative, zero

The enthalpy of vaporization of a liquid is 20 kJ mol⁻¹. Assuming ideal behaviour, calculate the change in internal energy when 1 mol of the liquid vaporizes at 60°C and 1 bar.

An ideal gas expands isothermally at 300 K from a volume of 10⁻³ m³ to 10⁻² m³ against a constant
external pressure of 10⁵ N m⁻². Calculate the work associated with this expansion using the chemistry sign convention.

$∆{\mathrm{H}}_{\mathrm{f}}^0$ (298K) of methanol is given by the chemical equation:

1. \(\mathrm{C}(\text { diamond })+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{H}_{2(\mathrm{~g})} \rightarrow \mathrm{CH}_3 \mathrm{OH}_{(\mathrm{l})}\)

2. \(\mathrm{CH}_{4(\mathrm{~g})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CH}_3 \mathrm{OH}_{(\mathrm{g})}\)

3. \(\mathrm{CO}_{(\mathrm{g})}+2 \mathrm{H}_{2(\mathrm{~g})} \rightarrow \mathrm{CH}_3 \mathrm{OH}_{(\mathrm{l})}\)

4. \(\mathrm{C}(\text { graphite })+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{H}_{2(\mathrm{~g})} \rightarrow \mathrm{CH}_3 \mathrm{OH}_{(\mathrm{l})}\)