For each of the following compounds, write a balanced thermochemical equation depicting the formation of one mole of the compound from its elements in their standard states and then look up H °f for each substance in Appendix C. (b) SO₃(g)

Video transcript

hey everyone were asked to write the formation equation for methane from the standard states of its elements and give its standard entropy of formation. So creating our formation equation, carbon in its standard state is going to be solid and this will react with our hydrogen gas and in order to end up with methane we need to add a coefficient of two prior to our hydrogen gas in order to completely balance out this reaction. Now to calculate the standard entropy affirmation of our methane, we know that we have to take the standard antelope meat of formation of our products minus the standard entropy of formation of our reactant. And we can go ahead and look at our textbooks in order to get these values. So plugging in these values, we see that we have one mole of our methane and we're going to multiply this by its standard entropy of formation which is negative 74,850 kg joules per mole. And again this was found in our textbooks and we also want to put into account our moles. So we'll have to multiply the number of moles by its respective standard entropy of formation of the compound. Next we're going to subtract the standard entropy of formation of our reactant since so we have one mole of carbon And we're going to multiply this by zero killer jewels per mole. Next we're going to add to mole of our hydrogen And we're going to multiply that by zero kg jewels per mole as well. Now when we calculate this out and cancel out all of our units, we end up with a standard anthem P a formation of negative 74,000, 100 50 kg joules per mole, which is going to be our final answer. Now, I hope that made sense and let us know if you have any questions.