Acid-Base Neutralization Acid-Base Neutralization ReactionsReactions

Chem 12Chem 12

AcidAcid + + Base Base Salt + Salt + WaterWater

• Orange juice + milk Orange juice + milk bad taste bad taste

• Evergreen shrub + concrete Evergreen shrub + concrete dead bush dead bush

• Under a pine tree + fertilizer Under a pine tree + fertilizer white white powderpowder

• HHCl + Cl + NaNaOHOH NaNaCl + Cl + HHOHOH salt water

Acid-Base Neutralization Acid-Base Neutralization ReactionsReactions

HClHCl(aq)(aq) + NaOH + NaOH(aq)(aq) NaCl NaCl(aq)(aq) + H + H22OO(l)(l)

• The products of an acid-base The products of an acid-base neutralization reaction are a salt made neutralization reaction are a salt made up of the positive ion of the base (Naup of the positive ion of the base (Na++) ) and the negative ion (Cland the negative ion (Cl--) of the acid, ) of the acid, and water. and water.

• Remember, in writing the correct Remember, in writing the correct formula for the salt, the total positive formula for the salt, the total positive charge of the ions in the salt must charge of the ions in the salt must equal the total negative charge of the equal the total negative charge of the ions in the salt. ions in the salt.

• Make sure you write the correct Make sure you write the correct formula for the products, salt and water formula for the products, salt and water first, then balancing the equation.first, then balancing the equation.

• The particles present in the HClThe particles present in the HCl(aq)(aq) solution solution due to ionization aredue to ionization are

HClHCl(g)(g) + H + H22OO(l)(l) H H33OO++(aq)(aq) + Cl + Cl--(aq)(aq)

OrOr

HClHCl(g)(g) H H++(aq)(aq) + Cl + Cl--(aq)(aq)

• The particles present in the NaOHThe particles present in the NaOH(aq)(aq) solution due to dissociation aresolution due to dissociation are

NaOHNaOH(aq)(aq) Na Na++(aq)(aq) + OH + OH--

(aq)(aq)

• Therefore, the ionic equation for the Therefore, the ionic equation for the reaction isreaction is

HH33OO++(aq)(aq) + Cl + Cl--

(aq)(aq) + Na + Na++(aq)(aq) + OH + OH--

(aq)(aq)

NaNa++(aq)(aq) + Cl + Cl--

(aq)(aq) + 2H + 2H22OO(l)(l) oror

HH++(aq)(aq) + Cl + Cl--

(aq)(aq) + Na + Na++(aq)(aq) + OH + OH--

(aq)(aq)

NaNa++(aq)(aq) + Cl + Cl--

(aq)(aq) + H + H22OO(l)(l)

• If we remove the spectator ions, NaIf we remove the spectator ions, Na++(aq)(aq)

and Cland Cl--(aq)(aq), we are left with the net ionic , we are left with the net ionic

equation for the acid-base equation for the acid-base neutralization reaction:neutralization reaction:

HH33OO++(aq)(aq) + OH + OH--

(aq)(aq) 2H 2H22OO(l)(l)

OrOr

HH++(aq)(aq) + OH + OH--

(aq)(aq) H H22OO(l)(l)

• Therefore, in an acid-base Therefore, in an acid-base neutralization reaction we can see neutralization reaction we can see that it is the hydronium ion from the that it is the hydronium ion from the acid that reacts with the hydroxide acid that reacts with the hydroxide ion from the base to produce neutral ion from the base to produce neutral water. water.

• Since the hydronium ion gives the Since the hydronium ion gives the acid its properties and the hydroxide acid its properties and the hydroxide ion gives the base its properties, the ion gives the base its properties, the acid-base reaction has resulted in the acid-base reaction has resulted in the neutralization of the properties of neutralization of the properties of both the acid and the base.both the acid and the base.

SAMPLE PROBLEM 1SAMPLE PROBLEM 1

For the acid-base neutralization of For the acid-base neutralization of nitric acid, HNOnitric acid, HNO3(aq)3(aq) and calcium and calcium hydroxide Ca(OH)hydroxide Ca(OH)2(aq)2(aq), write the , write the balanced:balanced:a) complete equationa) complete equationb) ionic equationb) ionic equationc) net ionic equationc) net ionic equation

a) a) The complete balanced equation The complete balanced equation for the reaction isfor the reaction is

Ca(OH)Ca(OH)2(aq)2(aq) + 2HNO + 2HNO3(aq)3(aq) Ca(NO Ca(NO33))2(aq)2(aq) + + 2H2H22OO(l)(l)

b)b) The ionic equation is The ionic equation is

CaCa2+2+(aq)(aq) + 2OH + 2OH--

(aq)(aq) + 2H + 2H++(aq)(aq) + 2NO + 2NO33

--(aq)(aq)

CaCa2+ 2+ (aq)(aq) + 2NO + 2NO33

--(aq)(aq) + 2H + 2H22OO(l)(l)

c)c) The net ionic equation is The net ionic equation is

2OH2OH--(aq)(aq) + 2H + 2H++

(aq)(aq) 2H 2H22OO(l)(l)

SAMPLE PROBLEM 2SAMPLE PROBLEM 2

For the acid-base neutralization of For the acid-base neutralization of perchloric acid, HClOperchloric acid, HClO4(aq)4(aq), and , and potassium hydroxide, KOHpotassium hydroxide, KOH(aq),(aq), write write the balanced:the balanced:a) complete equationa) complete equation

b) ionic equationb) ionic equation

c) net ionic equationc) net ionic equation

a)a) The complete balanced equation for the The complete balanced equation for the reaction isreaction is

HClOHClO4(aq)4(aq) + KOH + KOH(aq)(aq) KClO KClO4(aq)4(aq) + H + H22OO(l)(l)

b)b) The ionic equation isThe ionic equation is HH++

(aq)(aq) + ClO + ClO44--(aq)(aq) + K + K++

(aq)(aq) + OH + OH--(aq)(aq)

KK++(aq)(aq) + ClO + ClO44

--(aq)(aq) + H + H22OO(l)(l)

c)c) The net ionic equation is The net ionic equation is

OHOH--(aq)(aq) + H + H++

(aq)(aq) H H22OO(l)(l)