What is the heat of reaction when sulfur dioxide reacts with oxygen to form sulfur trioxide? 2so2(g) + o2(g) → 2so3(g) (∆hf0 so2(g) = –298.8 kj/mol; ∆hf0 so3(g) = –395.7 kj/mol) –201.9 kj –492.6 kj –694.5 kj –193.8 kj?

Answer : The enthalpy change for this reaction is -193.8 kJ.

Solution :

The balanced chemical reaction is,

The expression for enthalpy change is,

where,

n = number of moles

(as heat of formation of substances in their standard state is zero

Now put all the given values in this expression, we get

Therefore, the enthalpy change for this reaction is, -193.8 KJ

the volume increases

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.