If a chemical change is brought about by one or more methods in one or more steps, then the amount of heat absorbed or evolved during the complete course of reaction is same, which ever method was followed. This law is known as-

1. Le Chatelier's principle

2. Hess's law

3. Joule Thomson effect

4. Trouton's law

If 1.00 kcal of heat is added to 1.2 L of oxygen in a cylinder at constant pressure of 1.000 atm, the volume increases to 1.5 L, Hence $∆E$ for this process is:

1. 0.993 kcal

2. 1.0073 kcal

3. 0.0993 kcal

4. 1.00073 kcal

Heats of combustion of $C{H}_4, C_2{H}_4, C_2{H}_6$ are -890, -1411 and -1560 kJ/mole respectively. Which has the lowest fuel value in kJ/gm ?

1. $C{H}_4$

2. $C_2{H}_4$

3. $C_2{H}_6$

4. All same

The Kirchhoff's equation gives the effect of....on heat of reaction.

1. Pressure

2. Temperature

3. Volume

4. Molecularity

The temperature of 5 ml of a strong acid increases by $5^{\circ }$ when 5 ml of a strong base is added to it. If 10 ml of each is mixed, temperature should increase by-

1. $5^{\circ }$

2. ${10}^{\circ }$

3. ${15}^{\circ }$

4. cannot be known

For a reaction at equilibrium-

1. $∆G=∆G^{\circ }=0$

2. $∆G=0 but not ∆G^{\circ }$

3. $∆G^{\circ }=0 but not ∆G$

4. $∆G=∆G^{\circ }\ne 0$

Using only the following data:

(I) $F{e}_2{O}_3\left(s\right)+3CO\left(g\right)\rightleftharpoons 2Fe\left(s\right)+3C{O}_2\left(g\right);$
$∆H^{\circ }=-26.8 kJ$

(II) $$\begin{gathered} Fe\left(s\right)+C{O}_2\left(g\right)\rightleftharpoons FeO\left(s\right)+CO\left(g\right); \\ ∆H^{\circ }=+16.5 kJ \end{gathered}$$

the $∆H^{\circ }$ value, in kilojoules, for the reaction

$F{e}_2{O}_3\left(s\right)+CO\left(g\right)\to 2FeO\left(s\right)+C{O}_2\left(g\right)$ is calculated to be:

1. -43.3

2. -10.3

3. +6.2

4. +10.3

82 litres of carbon dioxide are produced at a pressure of 1 atm by the action of acid on a metal carbonate. The work done at room temp by the gas (in calories) in pushing back the atmosphere is 

1. 1000

2. 820

3. 1640

4. 2200

Among the following, the reaction for which $∆H=∆E$ is-

1. $PC{l}_5\left(g\right)\to PC{l}_3\left(g\right)+C{l}_2\left(g\right)$

2. $H_2\left(g\right)+C{l}_2\left(g\right)\to 2HCl\left(g\right)$

3. $C_2{H}_{5}OH\left(l\right)+3O_2\left(g\right)\to 2C{O}_2\left(g\right)+3H_{2}O\left(l\right)$

4. $C_2{H}_4\left(g\right)+H_2\left(g\right)\to C_2{H}_6\left(g\right)$

Enthalpy change when 1.00 g water is frozen at $0^{\circ }C,$ is :

$\left(∆H_{fus}=1.435 kcal mo{l}^{-1}\right)$

1. 0.0797 kcal

2. -0.0797 kcal

3. 1.435 kcal

4. -1.435 kcal