Hess' Law Flashcards
1
Q
What is the enthalpy change for elements?
A
Zero
2
Q
What is activation energy?
A
The minimum amount of energy needed to begin breaking reactant bonds and start a chemical reaction
3
Q
Are the products or reactants more stable?
A
The products are more stable in exothermic reactions
4
Q
Equation for working out enthalpy change?
A
Heat lost/gained = Mass of water x 4.18 x change in temperature
5
Q
Definition of a catalyst
A
A catalyst increases the rate of a reaction by providing an alternative reaction pathway with a lower activation energy. It is chemically unchanged at the end.
6
Q
What is Hess’ law?
A
The total enthalpy change of a reaction is always the same no matter which route is taken
