Physical Chemisty

Question 1

Standard conditions of temperature and pressure

Answer 1

298K

100KPa

Question 2

Bond enthalpy

Answer 2

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

Question 3

Average bond enthalpy

Answer 3

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

Question 4

Hess’ law

Answer 4

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

Question 5

Catalyst

Answer 5

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

Question 6

Heterogeneous catalysts

Answer 6

In a different physical state to reactants

Reaction happens on surface of the catalyst and increasing area means more can react

Question 7

Homogenous catalyst

Answer 7

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

Question 8

Catalyst used to make ethanol

Answer 8

Phosphoric Acid

Question 9

Le chataliers prunciple

Answer 9

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

Question 10

General reaction of equilibrium constant

Answer 10

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