Honors Chem Unit 10 Acids & Honors Chem Unit 10 Acids & BasesBases

Ch 14 & 15Ch 14 & 15 Properties of AcidsProperties of Acids::

– Sour TasteSour Taste– ElectrolytesElectrolytes– Change indicator colorsChange indicator colors– React with metals to form hydrogenReact with metals to form hydrogen– React with carbonates to form carbon React with carbonates to form carbon

dioxidedioxide– React with bases to form salt & waterReact with bases to form salt & water– Produces HProduces H+ + in waterin water– To name: Look at ending:To name: Look at ending:

» -ate polyatomic ions-ate polyatomic ions -ic acids -ic acids» -ite polyatomic ions -ite polyatomic ions -ous acids -ous acids» -ide monatomic ions-ide monatomic ions hydro –ic acid hydro –ic acid

Properties of basesProperties of bases::– BitterBitter– Feel SlipperyFeel Slippery– ElectrolytesElectrolytes– Change indicator colorsChange indicator colors– React with acids to produce React with acids to produce

salt & watersalt & water– Produce OHProduce OH- - in waterin water– To name: name the metal To name: name the metal

and hydroxideand hydroxide

Self ionization of water:Self ionization of water: HH22O + HO + H22O O H H33OO++ + OH + OH--

– Hydronium ion HHydronium ion H33OO++

– Hydroxide ion OHHydroxide ion OH--

Only 1X 10 Only 1X 10 –14–14 M of water molecules do M of water molecules do this so [Hthis so [H33OO++][OH][OH--] = 1X 10 ] = 1X 10 –14–14 M M

– If [HIf [H33OO++]=[OH]=[OH--] neutral solution] neutral solution

– If [HIf [H33OO++]>[OH]>[OH--] acidic solution] acidic solution

– If [HIf [H33OO++]<[OH]<[OH--] basic or alkaline solution ] basic or alkaline solution If the hydroxide concentration is 1 X 10If the hydroxide concentration is 1 X 10––

44M, what is the hydronium ion M, what is the hydronium ion concentration?concentration?

pH 1-6 7 8-14pH 1-6 7 8-14»Acid neutral baseAcid neutral base

pOH 14-8 7 6-1pOH 14-8 7 6-1

pH +pOH=14pH +pOH=14– Use to find one given the other.Use to find one given the other.– Find the pOH if the pH is 8.2.Find the pOH if the pH is 8.2.

[H[H++]= 10]= 10-pH-pH

– Use to find Use to find [H[H33OO++]] given the pH given the pH– Find the [HFind the [H++] given a pH of 11.5.] given a pH of 11.5.

[OH[OH--]= 10]= 10-pOH-pOH

– Use to find [OHUse to find [OH--] given the pOH] given the pOH– Find the [OHFind the [OH--] given a pOH of 7.5.] given a pOH of 7.5.

Formulas:Formulas: [H[H33OO++][OH][OH--] = 1 X 10 ] = 1 X 10 –14–14 M M Use to find one [] given the other []Use to find one [] given the other []

– Find the hydroxide ion concentration if Find the hydroxide ion concentration if the hydronium ion concentration is 1 X the hydronium ion concentration is 1 X 1010-5-5M. Is this acidic basic or neutral?M. Is this acidic basic or neutral?

pH=-log [HpH=-log [H33OO++]]– Use to find pH given [HUse to find pH given [H++]]– Find the pH if the hydronium ion Find the pH if the hydronium ion

concentration is 2.1 X 10concentration is 2.1 X 10-5-5M. M.

pOH= -log [OHpOH= -log [OH--]]– Use to find pOH given [OHUse to find pOH given [OH--]]– Find the pOH if the hydroxide ion Find the pOH if the hydroxide ion

concentration is 4.1 X 10concentration is 4.1 X 10-5-5M.M.

To measure pH:To measure pH:– Use acid/base indicators: change Use acid/base indicators: change

color based on [hydrogen ion ], color based on [hydrogen ion ], many types pg 604many types pg 604

– pH paper- have indicators on pH paper- have indicators on them them

– pH meterpH meter

Indicator LabIndicator Lab Purpose: use indicators to determine acids and Purpose: use indicators to determine acids and

basesbases Materials: pH paper, red and blue litmus paper, Materials: pH paper, red and blue litmus paper,

universal indicator, soap solution, HCl, NaOH, universal indicator, soap solution, HCl, NaOH, vinegar, ammonia, page protector vinegar, ammonia, page protector

Procedure:Procedure:– Create a chart of items to be tested and put it in page Create a chart of items to be tested and put it in page

protectorprotector– Create a chart for dataCreate a chart for data– Put 5 drops of each item to be tested on page protector Put 5 drops of each item to be tested on page protector

in appropriate boxin appropriate box– Tear red litmus into 5 pieces. Test each and record. Tear red litmus into 5 pieces. Test each and record. – Repeat for blue and pH paperRepeat for blue and pH paper– Put 1 drop of universal indicator in each sample and Put 1 drop of universal indicator in each sample and

record. record.

Indicator Lab QuestionsIndicator Lab Questions 1. Which of the items were acids? How do 1. Which of the items were acids? How do

you know?you know? 2. Which of the items were bases? How do 2. Which of the items were bases? How do

you know?you know? 3. Pick 3 different pH values and solve for 3. Pick 3 different pH values and solve for

the pOH, [Hthe pOH, [H++] & [OH] & [OH--]. Show formulas and ]. Show formulas and all work for credit. all work for credit.

Arrhenius acidArrhenius acid: Produce H: Produce H+ + ionion Arrhenius baseArrhenius base: Produce OH: Produce OH- - ionion Bronsted-Lowery AcidBronsted-Lowery Acid: H: H++ donor donor Bronsted Lowery BaseBronsted Lowery Base: H: H++ acceptor acceptor **More Broad definition than Arrhenius****More Broad definition than Arrhenius** Lewis acidLewis acid- can accept pr of e- to form a - can accept pr of e- to form a

covalent bond (Hcovalent bond (H++)) Lewis baseLewis base- can donate pr of e- to form a - can donate pr of e- to form a

covalent bond (OHcovalent bond (OH--) ) – Look for lone prLook for lone pr– ** is more broad than other two def.**** is more broad than other two def.**

Be able to identify conjugate acid base Be able to identify conjugate acid base pr:pr:– Acid becomes conjugate base Acid becomes conjugate base

– Base becomes conjugate acid Base becomes conjugate acid

AmphotericAmphoteric- can be acid or base- can be acid or base Identify the conjugate acid-base pairs Identify the conjugate acid-base pairs

in the following reactions.in the following reactions.         HH22SOSO44 + H + H22O O HSO HSO44

- - + H+ H33OO++

        HI(aq) + HHI(aq) + H22O(l) O(l) H H33OO++(aq) + I(aq) + I--(aq)(aq)

Strong acidStrong acid- completely ionizes - completely ionizes becomes weak CBbecomes weak CB

Weak acidWeak acid- incompletely ionizes - incompletely ionizes becomes strong CBbecomes strong CB

Can write ionization equation:Can write ionization equation: Can write acid dissociation constant Can write acid dissociation constant

(K(Kaa))

KKaa= [Products]/[Reactants]= [Products]/[Reactants]

– Don’t include waterDon’t include water– Smaller #=weaker acidSmaller #=weaker acid– Polyprotic acids- take 1 H at a timePolyprotic acids- take 1 H at a time

Also applies to bases called KAlso applies to bases called Kbb

Write the steps in the complete Write the steps in the complete ionization of Hionization of H22S.S.

Write the ionization equation and acid Write the ionization equation and acid ionization constant expression for the ionization constant expression for the following acids.following acids.– a.       HCla.       HCl– b.      HNOb.      HNO22

– c. Hc. H33POPO44

Write ionization equations and base Write ionization equations and base ionization constant expressions for the ionization constant expressions for the following bases.following bases.– a.   propylamine (Ca.   propylamine (C33HH77NHNH22))

How to find info about weak acidsHow to find info about weak acidsAcids

1. List major species

2. Write balanced equations for the H+ production

3. Using the values of K decide which will produce

4. Write the Keq for the dominant eq

5. Do ICE chart

6. Sub into the Keq

7. Solve for the easy way

8. Verify using 5% rule

9. Calculate [H+] and pH.

If given numbers fill in:If given numbers fill in: A .100M solution of ethanoic acid is A .100M solution of ethanoic acid is

partially ionized. The [Hpartially ionized. The [H++] is 1.34 X ] is 1.34 X 1010-3-3M. What is the KM. What is the Kaa of ethanoic of ethanoic acid?acid?

If acetic acid has a kIf acetic acid has a kaa= 1.8 X 10 = 1.8 X 10 -5-5, find , find

the pH, pOH, [Hthe pH, pOH, [H++], [OH], [OH--] of a 1.00M ] of a 1.00M solution. solution.

NeutralizationNeutralization- Double displacement- Double displacement– Acid + Base Acid + Base salt + water salt + water

nn11MM11VV11=n=n22MM22VV22

– 5.0 mL 0.5 M Nitric acid will neutralize how 5.0 mL 0.5 M Nitric acid will neutralize how much 2.0 M calcium hydroxide?much 2.0 M calcium hydroxide?

– 10.0 mL of 1.5 M Sulfuric acid will 10.0 mL of 1.5 M Sulfuric acid will neutralize how much 3.0 M aluminum neutralize how much 3.0 M aluminum hydroxide?hydroxide?

– Can find acid & base that form saltCan find acid & base that form salt»NaCl NaCl

»NaHCONaHCO33

SaltsSalts– Made from an acid & baseMade from an acid & base

Strong acid + strong baseStrong acid + strong base neutral neutral salt soln.salt soln.

Weak acid + strong base Weak acid + strong base basic salt basic salt soln.soln.

Strong acid + weak base Strong acid + weak base Acidic Acidic salt soln.salt soln.

Be able to predict the acid & base Be able to predict the acid & base that make the saltthat make the salt

BuffersBuffers- solution where the pH - solution where the pH remains constant when an acid/base remains constant when an acid/base are addedare added

Can absorb or release HCan absorb or release H++

– TitrationTitration- Use known to find unknown- Use known to find unknown– Need mol ratio for HNeed mol ratio for H++:OH-:OH-– Steps in titration:Steps in titration:

»Measure volume of acid soln. Of Measure volume of acid soln. Of [unknown] in flask[unknown] in flask

»Add indicatorAdd indicator»Measured volume of base [known] Measured volume of base [known] ‘standard’ are added until slight color ‘standard’ are added until slight color change (endpoint)change (endpoint)

»Use nMV=nMVUse nMV=nMV– A 25 mL soln of hydrochloric acid A 25 mL soln of hydrochloric acid

neutralized by 18mL of 1.0M NaOH. neutralized by 18mL of 1.0M NaOH. What is the [hydrochloric acid]?What is the [hydrochloric acid]?