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 $∆\mathrm{H}$ for vaporization of a liquid is \(20 \mathrm{~kJ} / \mathrm{mol}.\) Assuming ideal behaviour, the change in internal energy for the vaporization of \(1 \mathrm{~mol}\) of the liquid at \(60^{\circ} \mathrm{C}\) and 1 bar is close to:

The entropy change in the isothermal reversible expansion of 2 moles of an ideal gas from 10 to 100 L at 300 K is

1. $42.3 \mathrm{J} {\mathrm{K}}^{-1}$

2. $35.8 \mathrm{J} {\mathrm{K}}^{-1}$

3. $38.3 \mathrm{J} {\mathrm{K}}^{-1}$

4. $32.3 \mathrm{J} {\mathrm{K}}^{-1}$

An ideal gas expands isothermally from ${10}^{-3}{m}^3 to {10}^{-2} m^3$ at 300 K against a constant pressure of ${10}^5 N{m}^{-2}$. The work done by  the gas is:

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

1. C(diamond)+$\frac{1}{2}{O}_2$+2H₂$\to$CH₃OH

2. CH₄+$\frac{1}{2}{O}_2$$\to$CH₃OH

3. CO+2H₂$\to$CH₃OH

4. C(graphite)+$\frac{1}{2}{O}_2$+2H₂$\to$CH₃OH

4.8 g of C(diamond) on complete combustion evolves 1584 kJ of heat. The standard heat of the formation of gaseous carbon is 725 kJ/mol. The energy required for the given process will be:

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

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

A piston filled with 0.04 mol of an ideal gas expands reversibly from 50.0 mL to 375 mL at a constant temperature of 37.0ºC. As it does so, it absorbs 208 J of heat. The values of q and w for the process will be-
(R = 8.314 J/mol K) (ln 7.5 = 2.01)

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.

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

Entropy decreases during:

1. Crystallization of sucrose from solution

2. Rusting of iron

3. Melting of ice

4. Vaporization of camphor