Chemistry - enthalpy and rate constant (check)
posted by Farah on .
22. The rate of a chemical reaction is dependent on its ΔH. Do you agree or disagree with this statement? Briefly justify your answer.
I agree with the above statement, enthalpy is defined as the internal energy of the reactants and products therefore the chemical reaction will depend on the breaking and forming of the bonds which will then be either exothermic or endothermic.
23. What is the relationship between the units of the rate constant, k, and the overall reaction order?
The relationship between the units of the rate constant, k, and the overall reaction order is that it will determine the unit of k.
i am unsure of the above answer for the two question, can somebody please help me verify if they are correct
I don't agree with 22. DH is one factor that determines the spontaneity of the reaction (DG = DH -TDS) but it doesn't tell you anything about the rate. For example, the stable form of carbon is graphite. So diamonds will spontaneously degrade to graphite.(C graphite has DH = 0; C diamond has DH = 1.9 kJ/mol) However, the reaction is so slow that diamonds can be bought and sold as jewelry with no fear of them degrading significantly over many decades.
I don't agree with your answer to 23 either. Forgive me for being so direct but your answer appears to me that you don't know the answer so you put in a lot of words, talked around the answer and about the answer, but you never answered the question. If you really do know what you are talking about then I think the answer should be modified to a direct answer. If I wanted to answer this question I would look at the units for a first order reaction (easy enough to figure out), then look at a reaction that is first order with two reactants (and second order overall) and note the relationship, if any.