5.2 Hess's Law Flashcards Preview

Chemistry Chapter 5 - Energetics > 5.2 Hess's Law > Flashcards

Flashcards in 5.2 Hess's Law Deck (3)
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1
Q

Why can Hess’s law be used to work out unknown enthalpy changes from known ones?

A

The enthalpy change accompanying a chemical reaction is independent of the pathway between the initial and final states.

2
Q

What is the standard enthalpy change of formation?

A

The enthalpy change when one mole of the substance if formed form its elements in their standard states under standard conditions.

3
Q

What is the equation to solve problems where the enthalpy change of formation has been given?

A

Sum of enthalpy of products - sum of enthalpy of reactants.