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

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Chemistry

    O3 + NO --> O2 + NO2 (all in gas state) Calculate the change in enthalpy for the reaction at room temp. using the following data ^Hf: O3 = 143 NO = 90 NO2 = 33 So, I have 143+90--> X + 33. I don't know what the enthalpy of O2 …
  2. chemistry

    Calculate enthalpy change of reaction for the combustion of gaseous ethanol. C2H5OH + 3O2 >> CO2 + 3H2O. Using standard molar enthalpies of formation. C2H5OH -235.3 ( it's negative sign) CO2 -393.5 H2O -241.8 (1) Calculate the …
  3. chemsitry

    c. Use the enthalpy diagram provided above and apply Hess’s Law to determine the standard enthalpy of formation for C12O36H20N12 (s) using the results from part (a) and the following values: The standard enthalpy of formation of …
  4. gen Chem

    I've attempted this problem but not sure if i'm on the right track. Use the enthalpy diagram provided above and apply Hess’s Law to determine the standard enthalpy of formation for C12O36H20N12 (s) using the results from part (a) …
  5. chemistry

    A scientist measures the standard enthalpy change for the following reaction to be -53.4 kJ : Ca(OH)2(aq) + 2 HCl(aq) CaCl2(s) + 2 H2O(l) Based on this value and the standard enthalpies of formation for the other substances, the standard …
  6. chemistry

    A scientist measures the standard enthalpy change for the following reaction to be -53.4 kJ : Ca(OH)2(aq) + 2 HCl(aq) CaCl2(s) + 2 H2O(l) Based on this value and the standard enthalpies of formation for the other substances, the standard …
  7. Chemistry

    If calcium carbide has a standard enthalpy of formation of -59.8 kJ/mol and acetylene has a standard enthalpy of formation of 226.73 kJ/mol, what is the standard enthalpy change for the reaction?
  8. chemistry

    use the following data to calculate the mean bond enthalpy values for the C-H and C-C bonds. CH4(g)-C(g) + 4H(g) standard enthalpy change is +1648 kj/mol C2H6(g)-2C(g) + 6H(g) standard enthalpy change is +2820 kj/mol
  9. Chemistry

    Consider the isomerization equlibria of an alkene (C4H8) that co-exists as three isomers. (These 3 are in an equlibrium triangle) Reaction 1: cis-2-butene ⇔ trans-2-butene Reaction 2: cis-2-butene ⇔ 2-methylpropene Reaction …
  10. chemistry

    A scientist measures the standard enthalpy change for the following reaction to be -172.4 kJ : 2SO2(g) + O2(g) 2SO3(g) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of …

More Similar Questions