Sulfur dioxide, SO 2 ( g ) , can react with oxygen to produce sulfur trioxide, SO 3 ( g ) , by the reaction 2 SO 2 ( g ) + O 2 ( g ) ⟶ 2 SO 3 ( g ) The standard enthalpies of formation for SO 2 ( g ) and SO 3 ( g ) are Δ H ∘ f [ SO 2 ( g ) ] = − 296.8 kJ / mol Δ Of [ SO3 ( g ) ] = − 395.7 kJ / mol Calculate the amount of energy in the form of heat that is produced when a volume of 2.67 L of SO 2 ( g ) is converted to 2.67 L of SO 3 ( g ) according to this process at a constant pressure and temperature of 1.00 bar and 25.0 °C . Assume ideal gas behavior.

The amount of heat produced by the reaction is -21.36 kJ

Explanation:

Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles.

The equation used to calculate enthalpy change is of a reaction is:

For the given chemical reaction:

The equation for the enthalpy change of the above reaction is:

We are given:

Putting values in above equation, we get:

To calculate the number of moles, we use ideal gas equation, which is:

where,

P = pressure of the gas = 1.00 bar

V = Volume of the gas = 2.67 L

n = number of moles of gas = ?

R = Gas constant =

T = temperature of the mixture =

Putting values in above equation, we get:

To calculate the heat released of the reaction, we use the equation:

where,

q = amount of heat released = ?

n = number of moles = 0.108 moles

= enthalpy change of the reaction = -197.8 kJ/mol

Putting values in above equation, we get:

Hence, the amount of heat produced by the reaction is -21.36 kJ