Neutralization ReactionsNeutralization Reactions

• AcidAcid

HX(aq)HX(aq) + MOH(aq)MOH(aq) → MX(aq) +H2O(l)

+ BaseBase → Salt + Water

DR rxnDR rxn

Hydrochloric Acid + SodiumHydroxide

Is it balanced??

Sodium Chloride + Water

HCl(aq)HCl(aq) NaOH(aq)NaOH(aq)

NaCl(aq) +NaCl(aq) + HH22O(l)O(l)

HCl(aq) + NaOH(aq) NaCl(aq) + H2O

H+1(aq) + Cl-1(aq) + Na+1(aq) + OH-1(aq)

H2O(l) + Na+1(aq) + Cl-1(aq)

H+1(aq) + OH-1(aq) H2O(l)

Nitric Acid + Potassium Hydroxide

HNOHNO33(aq) + KOH(aq) (aq) + KOH(aq) KNO KNO33(aq) + H(aq) + H22O(l)O(l)

KK+1+1(aq) + NO(aq) + NO33-1-1(aq) + H(aq) + H22O(l)O(l)

HH+1+1(aq) + NO(aq) + NO33-1-1(aq) + K(aq) + K+1+1(aq) + OH(aq) + OH-1-1(aq) (aq)

HH+1+1(aq) + OH(aq) + OH-1-1(aq) (aq) H H22OO

Sulfuric Acid + Calcium Hydroxide

HH22SOSO44(aq) + Ca(OH)(aq) + Ca(OH)22(aq) (aq)

CaSOCaSO44(aq) + H(aq) + H22O(l)O(l)

HH22SOSO44 + Ca(OH) + Ca(OH)22 →→ CaSO CaSO44 + + 22 H H22OO

For any neutralization reaction For any neutralization reaction between an acid & base:between an acid & base:

net ionic equationnet ionic equation is always

HH+1+1(aq) + OH(aq) + OH-1-1(aq) (aq) H H22O(l)O(l)

pH changes during neutralization

• Start with an acid

• Add a base

• At neutralization

• Start with a base

• Add an acid

• At neutralization

pH < 7pH < 7pH pH

pH = 7pH = 7

pH > 7pH > 7

pH pH pH = 7pH = 7

HH+1+1(aq) + OH(aq) + OH-1-1(aq) (aq) H H22O(l)O(l)

1-to-1 relationship between H1-to-1 relationship between H+1+1and OHand OH-1-1

At neutralization point:neutralization point: # moles H# moles H+1+1 = # moles OH = # moles OH-1-1

Molarity of H+1

Molarity of HMolarity of H+1+1 = = moles Hmoles H+1+1

liters of solnliters of soln

Molarity of OH-1

Molarity of OHMolarity of OH-1-1 = = moles OHmoles OH-1-1

liters of solnliters of soln

At neutralization

Moles HMoles H+1+1 = Moles OH = Moles OH-1-1

(M(MH+1H+1) (V) (VH+1H+1) = (M) = (MOH-1OH-1) (V) (VOH-1OH-1))

(MA)( VA) = (MB)( VB)

• MA = molarity of H+1

• VA = volume of acid

• MB = molarity of OH-1

• VB = volume of base

True for:True for: • monoprotic monoprotic acid with acid with monohydroxymonohydroxy base base • diprotic diprotic acid with acid with dihydroxydihydroxy base base• triprotictriprotic acid with acid with trihydroxytrihydroxy base base

Molarity of HMolarity of H+1+1

• In HCl: molarity H+1 = molarity HCl

• In H22SO4:

molarity H+1 = 22(molarity H2SO4)• In H33PO4:

molarity H+1 = 33(molarity H3PO4)

Molarity of OHMolarity of OH-1-1

• In KOH:

molarity OH-1 = molarity KOH

• In Ca(OH)22:

molarity OH-1 = 22(molarity Ca(OH)2)

When # H’s ≠ # OH’s

(MA)(VA) = (MB)(VB)(#H(#H’’s)s) (#OH(#OH’’s)s)