From the following information, calculate the standard change of enthalpy for the combustion of coal.
C + O2 -> CO2
COMPOUND HEAT OF FORMATION
coal 0.0
carbon dioxide -393.5
water (l) -285.9
oxygen 0.0
dHrxn = (n*dHf products) - (n*dHf products)
So I would assume that the answer would be (-393.5)-(0)= -393.5
However, the problem lists the compound heat of formation for water also, which makes me think I have the wrong balanced equation up top, but at the same time no type of coal is specified, so there is no way to know the organic components it is made up of. Is this correct?
To calculate the standard change of enthalpy for the combustion of coal, we need to use the heat of formation values provided for each compound involved in the reaction.
The standard change of enthalpy (ΔH) for a reaction can be calculated using the equation:
ΔH = Σ(ΔH_products) - Σ(ΔH_reactants)
In this case, the reactant is coal (C) and the product is carbon dioxide (CO2).
The heat of formation (ΔH) for a compound is the heat change that occurs when one mole of the compound is formed from its constituent elements, with each element being in its standard state.
Using the heat of formation values given:
ΔH_products = ΔH_CO2
ΔH_reactants = ΔH_coal
Substituting the values:
ΔH = (ΔH_CO2) - (ΔH_coal)
ΔH = (-393.5) - (0.0)
ΔH = -393.5 kJ/mol
Therefore, the standard change of enthalpy for the combustion of coal is -393.5 kJ/mol.