Question

Consider the reaction in which 1 mol of aspartic acid(s) is converted to alanine(s) and CO2(g) at 25oC and 1bar pressure.

NH3+CH(CH2COOH)COO-(s) → CH3CHNH3+COO-(s) + CO2 (g)

(a) How much heat is evolved or absorbed?

(b) Write a cycle you could use to calculate the heat effect for the reaction at 50oC. State what properties of molecules you would need to know and what equations you would use to calculate the answer.

Answer 1

I have a doubt in part b) but I can help you in part a)

To do this, we need to know the enthalpies of formation for all this compound.

= fproducts - freactants.

I have found some values and this are:

f aspartic acid = -973.37 kJ/mol

f alanine = -562.7 kJ/mol

f CO2 = -393.52 kJ/mol

so:

rxn = (-562.7 - 393.52) - (-973.37)

rxn = 17.15 kJ/mol

The heat would be Q = * moles

but we have 1 mol, so Q = rxn = 17.15 kJ/mol

Hope this helps. I apologize again for not provide part b), but I hope part a) helps you.