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Flashcards in Physical Chemisty Deck (10):
1

Standard conditions of temperature and pressure

298K
100KPa

2

Bond enthalpy

Amount of energy needed to break one mole of the stated bond

3

Average bond enthalpy

Energy needed to break one mole of bonds in the gas phase averaged over many different compounds

4

Hess’ law

Regardless of the multiple stages of a reaction, the total enthalpy change for the reaction is the sum of all the changes

5

Catalyst

Lower activation energy by providing alternative pathways for the bonds to be broken and remade. The catalyst is left unchanged

6

Heterogeneous catalysts

In a different physical state to reactants
Reaction happens on surface of the catalyst and increasing area means more can react

7

Homogenous catalyst

Same physical state as the reactants
Usually is a aqueous catalyst, works by making an intermediate species which then reacts to from products and reform the catalyst

8

Catalyst used to make ethanol

Phosphoric Acid

9

Le chataliers prunciple

If you change the concentration, pressure or temperature of a reversible reaction, you tend to alter the position of equilibrium

10

General reaction of equilibrium constant

(D)d(E)e/(A)a(B)b