Thursday

August 28, 2014

August 28, 2014

Posted by **Anonymous** on Thursday, April 8, 2010 at 3:26pm.

2H2 + O2 - 2H2O delta H = -571.6 kJ

N2O5 + H2O - 2HNO3 deltaH = -73.7 kJ

1/2N2 + 3/2O2 + 1/2H2 - HNO3 delta H = -174.1 kJ

- Chem -
**DrBob222**, Thursday, April 8, 2010 at 4:13pmI believe you need to do the following:

reverse equation 1 and change sign of delta H.

Multiply equation 2 x 2 and reverse. Multiply delta H by 2 and change sign.

Multiply equation 3 by 4. Multiply delta H by 4.

Add the equations and add the delta Hs.

When you finish you should have

2N2 + 5O2 ==> 2N2O5 which is just twice what you are looking for so divide the coefficients by 2 throughout and divide total delta H by 2.

**Related Questions**

chemistry - CH4 + 2O2 ---> CO2 + 2H2O Delta H H2O= -285.8 kJ/mole Delta H CO2...

Chem - Does my work here look right? 3. One mole of an ideal gas expands ...

Chem - 2H2(g)+O2(g) ---> 2H2O(l) delta H= -572kJ/mole of O2 Calculate the ...

Chemistry - Data: C(graphite) + O2(g) forms CO2 (ga) Delta H = -393.5kJ H2(g) + ...

Chemistry - Which of the following reactions are spontaneous (favorable)? A] 2Mg...

Chemistry - Consider the following two thermochemical equations N2+2.5O2-> ...

Chemistry - Consider the following two thermochemical equations N2+2.5O2-> ...

Finding Delta G - The following reactions are important ones in catalytic ...

CHEM-HELP!!!! - help? how do i calculate the heat of formation of a solid? i ...

chemistry - use standard enthalpies of formation to calculate delta Hrxn for the...