Neutralization ReactionsNeutralization Reactions

Ex: HCl + NaOH NaCl + HOHEx: HCl + NaOH NaCl + HOH

These are double replacement reactionsThese are double replacement reactions

Ions switch partners. Water is formed.Ions switch partners. Water is formed.http://www.youtube.com/watch?v=8IRI5gPR5EY&safe=active

Neutralization Forms WaterNeutralization Forms Water

HH++ + OH + OH-- H H22OO

from acid from basefrom acid from base neutral neutral

This “net” reaction for neutralization is foundThis “net” reaction for neutralization is found

on Table I. It is an on Table I. It is an exothermicexothermic reaction. reaction.

Forming a SaltForming a Salt

(+) cation(+) cation from the base from the base

(-) (-) anionanion from the acid from the acid

combine to form a salt.combine to form a salt.

If If equal concentrationsequal concentrations of hydrogen ion H of hydrogen ion H++ and and hydroxide ions OHhydroxide ions OH-- are mixed, it results in a are mixed, it results in a neutral solution.neutral solution.

Ex:Ex:.1M LiOH + .1M HCl = Neutral Solution.1M LiOH + .1M HCl = Neutral Solution

pH = 7pH = 7

Completing and Balancing Completing and Balancing Neutralization EquationsNeutralization Equations

Write charges for ions in acid and base.Write charges for ions in acid and base.Switch ion partners. (+ ions stay in front!!)Switch ion partners. (+ ions stay in front!!)Do not bring over subscripts except if part Do not bring over subscripts except if part

of a polyatomic ion!of a polyatomic ion!Criss-Cross charges to balance formulas.Criss-Cross charges to balance formulas.Balance entire equation.Balance entire equation.

Name the acid, base and salt.Name the acid, base and salt.

You Try ItYou Try It

Complete equation and balance formulasComplete equation and balance formulasBalance equation.Balance equation.Name acid base and saltName acid base and salt

Ex:Ex: KOH + HKOH + H22SOSO44

KOH + HKOH + H22SOSO44 HOH + KHOH + K22SOSO44

Ex: Mg(OH)Ex: Mg(OH)22 + HNO + HNO33

Mg(OH)Mg(OH)22 + HNO + HNO33 HOH + Mg(NOHOH + Mg(NO33))22

HydrolysisHydrolysis

Opposite reaction to neutralizationOpposite reaction to neutralization

Salt + Water Salt + Water Acid + BaseAcid + Base

Parent Acid/BaseParent Acid/Base

If you know the salt involved you should If you know the salt involved you should be able to determine which acid and base be able to determine which acid and base it would form if water is added.it would form if water is added.

Salt + Water Salt + Water Acid + BaseAcid + Base

Ex: Ex:

NaCl with water (HOH) would form HCl and NaOHNaCl with water (HOH) would form HCl and NaOH

You Try ItYou Try It

Name the “parent” acid and base that Name the “parent” acid and base that would be produced from these salts.would be produced from these salts.

Ex:Ex: Potassium chloridePotassium chloride

Magnesium carbonateMagnesium carbonate

Let’s PracticeLet’s Practice

Which substance is always a product when Which substance is always a product when an Arrhenius acid in an aqueous solution an Arrhenius acid in an aqueous solution reacts with an Arrhenius base in an reacts with an Arrhenius base in an aqueous solution?aqueous solution?

(1) HBr(1) HBr

(2) KBr(2) KBr

(3) H(3) H22O O

(4) KOH (4) KOH

Which word equation represents a Which word equation represents a neutralization reaction?neutralization reaction?

(1) base + acid (1) base + acid →→ salt + water salt + water

(2) base +salt (2) base +salt →→ water + acid water + acid

(3) salt + acid (3) salt + acid →→ base + water base + water

(4) salt + water (4) salt + water →→ acid + base acid + base

What are the products of a reaction What are the products of a reaction between KOH(aq) and HCl(aq)?between KOH(aq) and HCl(aq)?

(1) H(1) H22 and KClO and KClO

        (2) KH and HClO(2) KH and HClO

(3) H(3) H22O and KCl O and KCl 

    (4) KOH and HCl (4) KOH and HCl

Sulfuric acid, HSulfuric acid, H22SOSO44(aq), can be used to (aq), can be used to

neutralize barium hydroxide,  Ba(OH)neutralize barium hydroxide,  Ba(OH)22(aq). (aq).

What is the formula for the salt produced What is the formula for the salt produced by this neutralization?by this neutralization?

(1) BaS        (1) BaS       

(3) BaSO(3) BaSO33

(2) BaSO(2) BaSO22       

(4) BaSO(4) BaSO44

Which compound could serve as a Which compound could serve as a reactant in a neutralization reaction?reactant in a neutralization reaction?

(1) NaCl     (1) NaCl    

(2) CH(2) CH33OHOH

(3) KOH     (3) KOH    

(4) CH(4) CH33CHOCHO

Answer: 3Answer: 3

TitrationsTitrations

Purpose:Purpose:

To determine the concentration of an acid To determine the concentration of an acid or base through a neutralization reaction.or base through a neutralization reaction.

Acid/Base TitrationAcid/Base Titration

Buret is filled with aBuret is filled with a

““standard solutionstandard solution” of” of

known concentration (M).known concentration (M).

Erlenmeyer Flask containsErlenmeyer Flask contains

solution of solution of unknown unknown conc..conc..

Indicator (phenolphthalein)Indicator (phenolphthalein)

added to the flask.added to the flask.

Acid/Base TitrationsAcid/Base Titrations

Slowly “titrate” or drip liquidSlowly “titrate” or drip liquid

into flask from buret untilinto flask from buret until

indicator changes color. indicator changes color.

This is the “This is the “endpointendpoint” or” or

““equivalence pointequivalence point”.”.

(Moles H+ = Moles OH-)

Record total volume (V) usedRecord total volume (V) used

from buret.from buret.

Titration FormulaTitration Formula

MMA x V x VA = M = MB x V x VB

Molarity Acid x Volume Acid = Molarity Base x Volume Base

Titration AppletTitration Applet

http://group.chem.iastate.edu/Greenbowe/sehttp://group.chem.iastate.edu/Greenbowe/sections/projectfolder/flashfiles/stoichiometry/actions/projectfolder/flashfiles/stoichiometry/acid_base.htmlcid_base.html

You Try It!You Try It!

A 50 ml sample of .2M HCl is neutralized byA 50 ml sample of .2M HCl is neutralized by

75ml of NaOH. What is the conc. of the base?75ml of NaOH. What is the conc. of the base?

HClHCl NaOHNaOH

.2M x 50ml = M.2M x 50ml = MBB x 75ml x 75ml

MMBB = .13M = .13M

Important NoteImportant Note

Multiply acid/base side of equation by Multiply acid/base side of equation by number of Hnumber of H++ or OH or OH-- ions it produces when ions it produces when dissociating!!!dissociating!!!

Ex: Ex:

HH22SOSO44 produces 2 H produces 2 H++ so you would so you would

multiply the acid side by “2”multiply the acid side by “2”

You Try It!You Try It!

How much of a .1M HHow much of a .1M H22SOSO44 solution is solution is

needed to neutralize 50 ml of a .05 KOHneeded to neutralize 50 ml of a .05 KOHsolution?solution?

HH22SOSO44 KOHKOH

2 x .1M x V2 x .1M x VA A = .05M x 50ml = .05M x 50ml

VVAA = 12.5 ml = 12.5 ml

Titration DemonstrationTitration Demonstration

http://www.youtube.com/watch?v=5BZ0MPIhttp://www.youtube.com/watch?v=5BZ0MPIgeEE&safe=activegeEE&safe=active

Let’s PracticeLet’s Practice

During which process can 10.0 milliliters of During which process can 10.0 milliliters of a 0.05 M HCl(aq) solution be used to a 0.05 M HCl(aq) solution be used to determine the unknown concentration of a determine the unknown concentration of a given volume of NaOH(aq) solution?given volume of NaOH(aq) solution?

(1) evaporation    (1) evaporation    (2) filtration(2) filtration(3) distillation       (3) distillation       (4) titration (4) titration

The data collected from a laboratory The data collected from a laboratory titration are used to calculate thetitration are used to calculate the

(1) rate of a chemical reaction(1) rate of a chemical reaction

(2) heat of a chemical reaction(2) heat of a chemical reaction

(3) concentration of a solution(3) concentration of a solution

(4) boiling point of a solution (4) boiling point of a solution

A student completes a titration by addingA student completes a titration by adding

12.0 ml of NaOH(aq) of unknown concentration12.0 ml of NaOH(aq) of unknown concentration

to 16.0 ml of 0.15 M HCl(aq). to 16.0 ml of 0.15 M HCl(aq).

What is the molar concentration of the NaOH(aq)?What is the molar concentration of the NaOH(aq)?

(1) 0.11 M     (1) 0.11 M    

(2) 1.1 M(2) 1.1 M

(3) 0.20 M     (3) 0.20 M    

(4) 5.0 M (4) 5.0 M