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Flashcards in Physical chem Deck (13):
1

Combustion

one mole of substance is burned completely in oxygen

2

Formation

one mole of substance is produced from its constituent elements

3

Neutralisation

one mole of water is formed when acid and base react

4

Define bond enthalpy

Break same bond in all molecules in one mole of gase

5

Exo?

Bonds formed, temp rise

6

Endo?

Bonds broken, temp decrease

7

Hess' law

If a reaction can take place by more than one route, the overall change is the same irrespective of route

8

Homogenous catalyst

Same phase a reactants

9

Heterogenous catalyst

Different phase
Absorbs gases on surface, weakens bonds decrease Ea, products are desorbed from surface

10

Why use catalysts?

Reduces temp and energy, no fossil fuel, lower atom economies reducing waste

11

Define dynamic eqm

Reached when rate of forward = backward
conc is constant

12

Define le chateliers system

Closed system at eqm is subject to change, system moves to minimise effect of change

13

Compromise

Low temp
High pressure
Compromise