Lowry -
Brolnsted model
}
>
anacidisa proton donor
important for the manufacture of
hydrochloric acid sulphuric acid nitric acid fertilizers Plastics and other useful
'
e' 9- - - .
>
products
abase is a proton acceptor
e. ammonium hydroxide
'
g.
Example / : Ñ+H>zOa ,
'
Chace, +
Hsotcaa,
Hclactsastheacidasitdonatesa proton / Ht )
-
Hzoactsasthebaseasit accepts the proton
A
II hydrogen atom contains only one proton and one electron When the hydrogen atom
:
.
loses an electron ,
a proton remains .
A proton is identified as a
hydrogen ion ( Ht )
'
Hzoa , Nlttcaq , OH caq )
-
Example
+
2 :
NHqg ,
+
Hzoactsastheacidasitdonatesa proton
NHsactsasthebaseas.it accepts the proton
examples water canactaseitheranacidorasa base
> both
in ,
>
amphiproticisa substance that can react asanacid with one substance ,
and can react
as abase with another substance ( H2O HCQIHSOÉ
,
)
Acid strength
> a
strong acid ionises
completely in an aqueous solution ionise completely ionise
Partially
> aweakacidionises partially in an aqueous solution T 14
strong acids weak acids strong weak
HCl acid HF acid
Hydrochloric Hydrofluoric HCl hydrochloric HF hydrofluoric
-
-
11-250<1 Sulphuric acid HZSO } Sulphurous acid HzSO¢ -
sulphuric Hasoz -
sulphurous
HNO , Nitric acid 1-131304 Phosphoric acid HNO , -
nitric HzPOa -
phosphoric
CHZCOOH Ethanol'C acid CHsCOOH -
ethanol'C
( COOH / z
Oxalic acid ( COOH )z -
oxalic
, Examples :
>
H NO , H2O NO3- +
Hzotcaq , hydronium
+
ion
caq ,
>
an acid ionises in water
>
ionisation is the reaction of a molecular substance with water to produce ions
proton donors
> in water , some acids are better
HCl + H2O Cliaqit Hs 07am
>
hydrochloric acid is a
good proton donor and so the solution consists largely of ions
>
equilibrium ties to the right ,
which means that this acid is nearly 100% ionized (conductive )
HCl is acid in water
> a
strong
The equilibrium constant ( Ka ) for acids HCl H2O Cliaq , +
Hsotcaq ,
strong
: +
value of Ka
very high ( > 10001
>
is
>
because the acid is almost 100% ionised
this means that the concentration of hydronium ions and chloride ions is
very high compared
>
to the concentration of the un -
ionised molecules ( HCI )
The equilibrium constant ( Ka ) for weak acids :
H Figs
+
Hzoa , Fiaq , +
Hs 0 Yaa ,
>
value of Ka is
very low equilibrium ties to the left
>
because the acid ionises only partially in water
> this means that the concentration of hydronium ions and fluoride ions is low compared to
the concentration of the un -
ionised molecules ( HF )
Equations for the ionisation of other acids
Hzsoacaql +
211-20111 2 Hzotcaq , +
5042 Iaql
CH } COOH caql H 20111 ¥ Hzotcaq ,
-
+ +
CH , COO ( aat
Hs POA ( aq )
+
3h20 (1) ¥3 Hzotcaq , +
POE( aq )
Brolnsted model
}
>
anacidisa proton donor
important for the manufacture of
hydrochloric acid sulphuric acid nitric acid fertilizers Plastics and other useful
'
e' 9- - - .
>
products
abase is a proton acceptor
e. ammonium hydroxide
'
g.
Example / : Ñ+H>zOa ,
'
Chace, +
Hsotcaa,
Hclactsastheacidasitdonatesa proton / Ht )
-
Hzoactsasthebaseasit accepts the proton
A
II hydrogen atom contains only one proton and one electron When the hydrogen atom
:
.
loses an electron ,
a proton remains .
A proton is identified as a
hydrogen ion ( Ht )
'
Hzoa , Nlttcaq , OH caq )
-
Example
+
2 :
NHqg ,
+
Hzoactsastheacidasitdonatesa proton
NHsactsasthebaseas.it accepts the proton
examples water canactaseitheranacidorasa base
> both
in ,
>
amphiproticisa substance that can react asanacid with one substance ,
and can react
as abase with another substance ( H2O HCQIHSOÉ
,
)
Acid strength
> a
strong acid ionises
completely in an aqueous solution ionise completely ionise
Partially
> aweakacidionises partially in an aqueous solution T 14
strong acids weak acids strong weak
HCl acid HF acid
Hydrochloric Hydrofluoric HCl hydrochloric HF hydrofluoric
-
-
11-250<1 Sulphuric acid HZSO } Sulphurous acid HzSO¢ -
sulphuric Hasoz -
sulphurous
HNO , Nitric acid 1-131304 Phosphoric acid HNO , -
nitric HzPOa -
phosphoric
CHZCOOH Ethanol'C acid CHsCOOH -
ethanol'C
( COOH / z
Oxalic acid ( COOH )z -
oxalic
, Examples :
>
H NO , H2O NO3- +
Hzotcaq , hydronium
+
ion
caq ,
>
an acid ionises in water
>
ionisation is the reaction of a molecular substance with water to produce ions
proton donors
> in water , some acids are better
HCl + H2O Cliaqit Hs 07am
>
hydrochloric acid is a
good proton donor and so the solution consists largely of ions
>
equilibrium ties to the right ,
which means that this acid is nearly 100% ionized (conductive )
HCl is acid in water
> a
strong
The equilibrium constant ( Ka ) for acids HCl H2O Cliaq , +
Hsotcaq ,
strong
: +
value of Ka
very high ( > 10001
>
is
>
because the acid is almost 100% ionised
this means that the concentration of hydronium ions and chloride ions is
very high compared
>
to the concentration of the un -
ionised molecules ( HCI )
The equilibrium constant ( Ka ) for weak acids :
H Figs
+
Hzoa , Fiaq , +
Hs 0 Yaa ,
>
value of Ka is
very low equilibrium ties to the left
>
because the acid ionises only partially in water
> this means that the concentration of hydronium ions and fluoride ions is low compared to
the concentration of the un -
ionised molecules ( HF )
Equations for the ionisation of other acids
Hzsoacaql +
211-20111 2 Hzotcaq , +
5042 Iaql
CH } COOH caql H 20111 ¥ Hzotcaq ,
-
+ +
CH , COO ( aat
Hs POA ( aq )
+
3h20 (1) ¥3 Hzotcaq , +
POE( aq )
