Help!

[bard]

calculate delta h of this eq
2N2 + 5o2 -> 2N2O5
giventhis data
h2 + 1/2o2 -> h20
and delta h of that is -285.5
n2o5 + h2o -> 2nho3 delta h -76.5
and
1/2n2 + 3/2 o2 + 1/2h2 -> hno3 delta h -170.3

[Cantari]

Are you familiar with Hess's Law? Rearrange the bottom 3 equations by modifying them and combining them to make it look like the unknown.

[Gokul43201]

bard, you have to show what you know and have tried, before we can help you.