The enthalpy of neutralization of which of the following acids and bases is nearly –13.6 Kcal [Roorkee 1999]

(1) HCN and NaOH

(2) HCl and KOH

(3) HCl and HCN

(4) HCl and NH₄OH

What is the work done when one mole of an ideal gas undergoes isothermal expansion from an initial pressure of 10 atm to a final pressure of 1 atm at a constant temperature of 300 K? (Gas constant = 2 calorie )
1. 938.8 cal
2. 1138.8 cal
3. 1381.8 cal
4. 1581.8 cal

Joule-Thomson expansion is [JIPMER 2000]

(1) Isobaric

(2) Isoenthalpic

(3) Isothermal

(4) None of these

In an adiabatic expansion of an ideal gas-

1. W = –ΔE

2. W = ΔE

3. ΔE = 0

4. W = 0

Consider the given 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

Which of the following statements is not true regarding the expansion of one mole of an ideal gas that expands freely and adiabatically into a vacuum until its volume doubles?

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