Post a New Question

Chem

posted by .

Change in enthalpy problem. Consider the reaction represented below. Referring to the data in the table below, calculate the standard enthalpy change for the reaction at 25 degrees C.

O3(g)+NO(g)-->O2(g)+NO2(g)

Standard enthalpy of formation in kJ/mol:

O3(g) 143
NO(g) 90
NO2(g) 33

I am sure this isn't a hard problem, but I can't really remember how to do it.

  • Chem -

    delta Hreaction = delta Hproducts - delta Hreactants

  • Chem -

    Ok, so I have DeltaHrxn=(X+90)-(143+90). How do you calculate the enthalpy of O2 (X above) when it is not given to you. Am I even doing that right?

  • Chem -

    No. Re-read my answer. I said
    PRODUCTS - REACTANTS.
    You have one of the reactants on the product side.
    DHrxn = DH products - DH reactants.
    DHrxn = (O2 + NO2) - (O3 + NO)
    DHrxn = (0 + 33) - (143 + 90) = ??

  • Chem -

    drbob222 is correct . the answer is 200. DUh!!

  • Chem -

    It's -200. not 200

Answer This Question

First Name:
School Subject:
Answer:

Related Questions

More Related Questions

Post a New Question