In an adiabatic expansion of an ideal gas-

1. W = –ΔE

2. W = ΔE

3. ΔE = 0

4. W = 0

For the reaction

\(C H_{3} C O O H \left(\right. l \left.\right)+ 2 O_{2} \left(\right. g \left.\right) \)
\(\rightleftharpoons 2 C O_{2} \left(\right. g \left.\right)+ 2 H_{2} O \left(\right. l \left.\right)\)
at 25°C and 1 atm. pressure, ΔH = –874 kJ. The change in internal energy (ΔE) is:

1. – 874 kJ
2. – 971.53 kJ
3. + 971.53 kJ
4. + 874 kJ

One mole of an ideal gas is allowed to expand freely and adiabatically into a vacuum until its volume has doubled. A statement that is not true concerning this expression is [Pb. PMT 1998]

1. ΔH = 0

2. ΔS = 0

3. ΔE = 0

4. W = 0

At 27°C, one mole of an ideal gas is compressed isothermally and reversibly from a pressure of 2 atm to 10 atm. The values of ΔE and q are (R = 2)

(1) 0, – 965.84 cal

(2) – 965.84 cal, + 965.84 cal

(3) + 865.58 cal, – 865.58 cal

(4) – 865.58 cal, – 865.58 cal

ΔE° of combustion of isobutylene is –X kJ mol^–1. The value of ΔH° is [DCE 2004]

1. = ΔE°

2. > ΔE°

3. = 0

4. < ΔE°

An ideal gas expands in volume from 1 × 10^–3 m³ to 1 × 10^–2 m³ at 300 K against a constant pressure of 1 × 10⁵ Nm^–2. The work done is [AIEEE 2004]

(1) 270 kJ

(2) –900 kJ

(3) –900 J

(4) 900 kJ

The spontaneous flow of heat is always

1. From low to high pressure

2. From high to high pressure

3. Unidirectional from lower temperature to higher temperature

4. Unidirectional from the higher to lower temperature

The mixing of non-reacting gases is generally accompanied by

1. Decrease in entropy

2. Increase in entropy

3. Change in enthalpy

4. Change in free energy

An irreversible process occuring isothermally in an isolated system leads to

(1) Zero entropy

(2) An increase in the total entropy of the system

(3) A decrease in the total entropy of the system

(4) None of these

The entropy values (in JK^-1 mol^-1) of H_2(g) = 130.6, Cl_2(g) = 223.0 and HCl_(g) = 186.7 at 298 K and 1 atm pressure. Then entropy change for the reaction ${\mathrm{H}}_{2\left(\mathrm{g}\right)}+{\mathrm{Cl}}_{2\left(\mathrm{g}\right)}\to 2{\mathrm{HCl}}_{\left(\mathrm{g}\right)}$ is

(1) + 540.3

(2) + 727.3

(3) – 166.9

(4) + 19.8