Acids
21. 1
and Bases
DEFININa AN ACID
Bronsted Lowry definitions
Acid - proton donor
Base proton acceptor
H S0t HNO, ’ H,SVO t HsO,
b sufuric acId acts as an acid
’ nibnc acid acts as a base
Watec as aM acid and base
Whethes a species acts as an acid oa base depends on the reactants.
Wate can at as eithe an acid or abaSe
water a cts as a base
Ha 4+
L water ats as an aud
Protons can be represented in an aqucous soution by H rath
taan HgQ', nhch simplitues equatons.
lonic product o nater
He0 +
acid base reactim wheone woater oleale don atesa
proton to another Ths s revestble aad can also be
written asi
t OH
This cqulibum IS establ1shed n all aqueous solutians.
Equilibum express1ni
CH*J[OH
CH,0J
(Kuw
ot water (Kw
product of K x CH,0))
-i4 mol
Kn
248k Kw I.Ox I014
L at 248k,
, 21.2 THE PH SCALE
- The smale the pH, the qrea ter the concentration ot H
A diffene of one pH number means a tentold ditteren a ln UJ
e.g. pt 2 has ten tmes tle CH' t pt 3
Calulating the plt ot water
Pue wat er is neutral Sme LH] LOH
K i LH1[OHJ
1.0 x| 0
7
pt log ie [1-0x|0): Z.00
Always g1ve ph values to 2d.p.
Calulatung pH ot water at 323k (ki SI.3 x10)
LH]: JsI.3x10-1% 7. 162 10
Although the pt is less than 7.00, the wate Is stl neutral
LH1: LoHJ. The value ot Kw inueases wth templature
and tne plt ot wate deceases at inreased tempeatures
H,0 H* +OH H+S7.3 w mol
the
lo oppose the cease in temperat we, the equilbum will shitt
to tavOr the endothermic direction. This
lncreaSes the nuaber
of watee moleules that dissouate and so there wll be a
concntraticn ot H" and ot . This nreases the value ot hught
ond so deceases t i pH
Measuing ph
-lndicotor poper
|adiator solutim (phenol ph thaler, unives a indiccator)
pH mee (more preise)
can be conneted to a data logge for
continuous monitorag
21. 1
and Bases
DEFININa AN ACID
Bronsted Lowry definitions
Acid - proton donor
Base proton acceptor
H S0t HNO, ’ H,SVO t HsO,
b sufuric acId acts as an acid
’ nibnc acid acts as a base
Watec as aM acid and base
Whethes a species acts as an acid oa base depends on the reactants.
Wate can at as eithe an acid or abaSe
water a cts as a base
Ha 4+
L water ats as an aud
Protons can be represented in an aqucous soution by H rath
taan HgQ', nhch simplitues equatons.
lonic product o nater
He0 +
acid base reactim wheone woater oleale don atesa
proton to another Ths s revestble aad can also be
written asi
t OH
This cqulibum IS establ1shed n all aqueous solutians.
Equilibum express1ni
CH*J[OH
CH,0J
(Kuw
ot water (Kw
product of K x CH,0))
-i4 mol
Kn
248k Kw I.Ox I014
L at 248k,
, 21.2 THE PH SCALE
- The smale the pH, the qrea ter the concentration ot H
A diffene of one pH number means a tentold ditteren a ln UJ
e.g. pt 2 has ten tmes tle CH' t pt 3
Calulating the plt ot water
Pue wat er is neutral Sme LH] LOH
K i LH1[OHJ
1.0 x| 0
7
pt log ie [1-0x|0): Z.00
Always g1ve ph values to 2d.p.
Calulatung pH ot water at 323k (ki SI.3 x10)
LH]: JsI.3x10-1% 7. 162 10
Although the pt is less than 7.00, the wate Is stl neutral
LH1: LoHJ. The value ot Kw inueases wth templature
and tne plt ot wate deceases at inreased tempeatures
H,0 H* +OH H+S7.3 w mol
the
lo oppose the cease in temperat we, the equilbum will shitt
to tavOr the endothermic direction. This
lncreaSes the nuaber
of watee moleules that dissouate and so there wll be a
concntraticn ot H" and ot . This nreases the value ot hught
ond so deceases t i pH
Measuing ph
-lndicotor poper
|adiator solutim (phenol ph thaler, unives a indiccator)
pH mee (more preise)
can be conneted to a data logge for
continuous monitorag
