Summary A level chemistry summarised equation sheet for the whole subject

, Revision notes

cixs
energe
3
Enthalpy
1 4 1
change
-
.
. .




DH break bonds
energy to
·
+ DH endothermic to make bod
is
reaction
energy
=
= +


-

Ah =
exothermic reaction
c -
ve)




Enthalpy of formation CDHHS) :
The enthalpy change when one mole of a substance is formed from its constituent elements


under Standard States and Standard Condition


equation : [AP products) -
EDH + creactants)




Enthalpy of Combustion (ACHP) , The
enthalpy change when one more of a substance is
completely
burned in under Standard states
Oxygen and stand and conditioned
.




3 1 4 2 . . . -




Calorimetry
↳ Experimental Method for finding enthalpy change by Semperature Over
measuring time .
This measured
change in T is proportion ar to



energy change
.
q =
MC T =energy change -Specific heat capacity

m =
Mass(g) AT =
semperature change


Specific heat capacity - The energy required to raise Ig of substance by IK without a
change ofState .




DH = I n = moles
N




DHT
. 1 4 3- Hese's A >

H
3 Law e
g
.
.
.




·

Energy in a reaction system must be conserved .
=
H + H

Hess's Law is used
DH DH2
to determine the enthalpy change of a reaction
-
C
that cannot be found directly using an experimental method