The enthalpy changes for the following processes are listed below:
Cl₂(g) = 2Cl(g), 242.3 kJ mol^–1
I₂(g) = 2I(g), 151.0 kJ mol^–1
ICl(g) = I(g) + Cl(g), 211.3 kJ mol^–1
I₂(s) = I₂(g), 62.76 kJ mol^–1
Given that the standard states for iodine and chlorine are I₂(s) and Cl₂(g), the standard enthalpy of formation for ICl(g) is

• –14.6 kJ mol^–1

• –16.8 kJ mol^–1

• +16.8 kJ mol^–1

• +244.8 kJ mol^–1

Define thermodynamics.

What do you understand by the terms: the system and surroundings?

Classify the following into different types of systems:
(i) Tea placed in a cup
(ii) Tea placed in a tea-pot
(iii) Tea placed in a thermosflask. 

Define a closed system.

Define an isolated system.

Define intensive properties.

Define extensive properties.

Why all living systems need to be 'open systems'?

Define state variables of a system.

From thermodynamic point of view, to which system the animals and plants belong?