enpalthy

Question 1

Answer 1

Question 2

Standard enthalpy change of
combustion ΔcH⦵

Answer 2

The standard enthalpy change that
occurs when one mole of a substance completely combusts with excess
oxygen under standard states and conditions.

Only exothermic

Question 3

Standard enthalpy change of
neutralisation ΔneutH⦵

Answer 3

The standard enthalpy change that occurs when an acid and base react to form one mole of water under standard states and conditions.

Only exothermic

Question 4

q= ?

Answer 4

Question 5

Answer 5

Question 6

calculating average bond empalthy

Answer 6

Question 7

Definition of Average bond enpalthy.

Answer 7

when one mole of bonds
✓
of (gaseous covalent) bonds is broken ✓

the value is always
endothermic and positive.

Question 8

Answer 8

Question 9

Answer 9

Question 10

Answer 10

Question 11

Answer 11

Question 12

Answer 12

Question 13

Answer 13

Question 14

Enpalthy of combustion

Answer 14

Reactants - Minus products

Question 15

Empalthy of formation

Answer 15

Products - Reactants

Question 16

How to calculate enpalthy change of combusion

Answer 16

1. find q using q=mct.
   tip if the mass is in cm then use that value for the mass. If there are two cm then add these together.
   ALWAYS DIVIDE BY 1000 to get from j to kj
   m is also the mass of water too.
2. find moles

make sure ratio is the same

and then do q/mols

Question 17

Answer 17

Question 18

Answer 18

Question 19

Answer 19

Catalyst lowers the activation energy (by providing an
alternative route) ✓
QWC - (With a catalyst a) greater proportion of
molecules with energy greater than activation energy✓

Question 20

Answer 20

Question 21

Answer 21

Question 22

Answer 22

Question 23

Answer 23

Question 24

Answer 24

Question 25

Answer 25

Question 26

Answer 26

Question 27

Answer 27

Question 28

Answer 28

Question 29

Answer 29