Hess's law is the method of obtaining heat values derived from several steps to obtain the standard enthalpy of the reaction. These steps includes several standard enthalpy change of the intermediate reactions. You can simply view it this way: you have to show how the equation P4O10 (s) + 6PCl5 (g) -> 10Cl3PO (g) is formed from the lists of intermediate reaction written (numbers 1-4)

There are several steps to consider when manipulating values via hess's law.

1. when you flip the equation, you change the sign of the delta H

2. when you double the reaction,...

(The entire section contains 297 words.)

## Unlock This Answer Now

Start your **48-hour free trial** to unlock this answer and thousands more. Enjoy eNotes ad-free and cancel anytime.

Already a member? Log in here.