BRN – place these items in the T-chartBRN – place these items in the T-chart

Acid Neutral Base

SafetySafety

WEAR goggles at ALL times!

Today we are working with HCl (Hydrochloric acid) CaCl2 and NaOH which can irritate skin. If some gets on your skin rinse immediately with water.

Dispose of chemicals down sink.

WEAR goggles at ALL times!

Today we are working with HCl (Hydrochloric acid) CaCl2 and NaOH which can irritate skin. If some gets on your skin rinse immediately with water.

Dispose of chemicals down sink.

Lab Activity- Part 1Lab Activity- Part 1

Put small amounts of 12 different substances in the sample well plates.

Use a small sample of red, blue, and pH paper to dip into well plate and record observations

Put small amounts of 12 different substances in the sample well plates.

Use a small sample of red, blue, and pH paper to dip into well plate and record observations

Lab Activity- Part 2Lab Activity- Part 2

Using the pH values that you found in part 1, place the substances on the pH scale.

Using the pH values that you found in part 1, place the substances on the pH scale.

Share Out!Share Out!

Did the results of the lab activity surprise you?

Which substances are acids?

Which are bases?

What happened with neutral substances?

What were some of the color patterns you saw?

Did the results of the lab activity surprise you?

Which substances are acids?

Which are bases?

What happened with neutral substances?

What were some of the color patterns you saw?

7

11

5

4

3

2

1

89

10

6

12

13

14

Acid/Base NotesAcid/Base Notes

New Section in Table of ContentsNew Section in Table of Contents

What is an acid?What is an acid?

What is an acid?What is an acid?

KC 1: Properties of acidsTart, sour taste

Conduct electricity well

React with many metals

Contain H+ ion

Generate hydronium ions – H3O+

pH less than 7

Neutralizes bases

KC 1: Properties of acidsTart, sour taste

Conduct electricity well

React with many metals

Contain H+ ion

Generate hydronium ions – H3O+

pH less than 7

Neutralizes bases

How are acids measured?How are acids measured?

KC 2: pH is a logarithmic scale that express the concentrations of hydrogen ions in aqueous solutions

pH = - log[H+]

KC 2: pH is a logarithmic scale that express the concentrations of hydrogen ions in aqueous solutions

pH = - log[H+]

pH ScalepH Scale

Weak vs. Strong acidsWeak vs. Strong acids

KC 3: A strong acid fully dissociates into H+ cations and its respective anion.

KC 4: Weak Acids do not ionize completely

Strong versus weak is not related to pH.

KC 3: A strong acid fully dissociates into H+ cations and its respective anion.

KC 4: Weak Acids do not ionize completely

Strong versus weak is not related to pH.

Common AcidsCommon Acids

HCl- hydrochloric- stomach acid

H2SO4- sulfuric acid - car batteries

HNO3 – nitric acid - explosives

HC2H3O2- acetic acid - vinegar

H2CO3-carbonic acid – sodas

H3PO4- phosphoric acid - flavorings

HCl- hydrochloric- stomach acid

H2SO4- sulfuric acid - car batteries

HNO3 – nitric acid - explosives

HC2H3O2- acetic acid - vinegar

H2CO3-carbonic acid – sodas

H3PO4- phosphoric acid - flavorings

What is a base?What is a base?

What is a base?What is a base?

KC 5 Properties of Bases:pH greater than 7Feels slipperyDissolves fats and oils

Usually forms OH- ions in solutionNeutralizes acidsCommonly used as cleaning products.

KC 5 Properties of Bases:pH greater than 7Feels slipperyDissolves fats and oils

Usually forms OH- ions in solutionNeutralizes acidsCommonly used as cleaning products.

Weak vs. strong basesWeak vs. strong bases

Key Concept 6: A strong base fully dissociates into OH- anions and its respective cations.

Weak Bases: ammonia; potassium carbonate, sodium carbonate

Strong Bases: sodium hydroxide; sodium phosphate; barium hydroxide; calcium hydroxide

Strong versus weak is not related to pH.

http://phet.colorado.edu/en/simulation/acid-base-solutions

Key Concept 6: A strong base fully dissociates into OH- anions and its respective cations.

Weak Bases: ammonia; potassium carbonate, sodium carbonate

Strong Bases: sodium hydroxide; sodium phosphate; barium hydroxide; calcium hydroxide

Strong versus weak is not related to pH.

http://phet.colorado.edu/en/simulation/acid-base-solutions

Common BasesCommon Bases

NaOH- sodium hydroxide (LYE) soaps, drain cleaner

Mg (OH)2 - magnesium hydroxide-antacids

Al(OH)3-aluminum hydroxide-antacids, deodorants

NH4OH-ammonium hydroxide- “ammonia”

NaOH- sodium hydroxide (LYE) soaps, drain cleaner

Mg (OH)2 - magnesium hydroxide-antacids

Al(OH)3-aluminum hydroxide-antacids, deodorants

NH4OH-ammonium hydroxide- “ammonia”

Acids and BasesAcids and Bases

KC 7: Arrhenius acid and base:

Acids increase H+ cation concentration in water

Bases increase OH- anion concentration in water

KC 7: Arrhenius acid and base:

Acids increase H+ cation concentration in water

Bases increase OH- anion concentration in water

HCl(aq) + H2O(l) H3O+(aq) + Cl-

Increases H+

Increases OH-

HCl(aq) + H2O(l) H3O+(aq) + Cl-

Loses a proton

Gains a proton

Acids and BasesAcids and Bases

KC 8: Brønsted-Lowry acid and base:

Acids are proton (H+) donators

Bases are proton acceptors

KC 8: Brønsted-Lowry acid and base:

Acids are proton (H+) donators

Bases are proton acceptors

Conjugate Acid/BaseConjugate Acid/Base

KC 9: Conjugate acid – an acid that forms when a base gains a proton

KC 10: Conjugate base – a base that forms when an acid loses a proton

KC 9: Conjugate acid – an acid that forms when a base gains a proton

KC 10: Conjugate base – a base that forms when an acid loses a proton

Acid Conjugate Acid

Conjugate BaseBase

Acids and BasesAcids and Bases

KC 11: Amphoteric – substance that has the properties of an acid and the properties of a base

KC 11: Amphoteric – substance that has the properties of an acid and the properties of a base

H2O (l) + H2O (l) ↔ H3O+ (aq) + OH- (aq)Acid Conjugate Acid

Conjugate BaseBase

pH pH pH = -log [H+]

pH is a measure of the number of hydronium ions

pH is a measure of the number of hydronium ions

2H2O ↔ H3O+ + OH-2H2O ↔ H3O+ + OH-

pH PaperpH Paper

pH paper changes color to indicate a specific pH value.

pH paper changes color to indicate a specific pH value.

IndicatorsIndicators

Key Concept 12: Chemical dyes whose color are affected by acidic and basic solutions are called acid-base indicators.

Not all indicators show when the pH is 7.

Key Concept 12: Chemical dyes whose color are affected by acidic and basic solutions are called acid-base indicators.

Not all indicators show when the pH is 7.

IndicatorsIndicators The following table can be used to see when

each indicator should be used: The following table can be used to see when

each indicator should be used:

Natural IndicatorsNatural Indicators There are some natural indicators such as cabbage

juice or hydrangeas. There are some natural indicators such as cabbage

juice or hydrangeas.

Ionization of WaterIonization of Water

H2O + H2O ↔ H3O+ + OH-

[H3O+] = [OH-] = 1.00 x 10-7

[H3O+][OH-] = Kw = (1.00 x 10-7)(1.00 x 10-7) = 1.00 x 10-14

H2O + H2O ↔ H3O+ + OH-

[H3O+] = [OH-] = 1.00 x 10-7

[H3O+][OH-] = Kw = (1.00 x 10-7)(1.00 x 10-7) = 1.00 x 10-14

Concentrations and KwConcentrations and Kw

Solution [H3O+] [OH-] Kw = [H3O+] [OH-]

Pure water 1.0 x 10-7 1.0 x 10-7 1.0 x 10-14

0.10M strong acid 1.0 x 10-1 1.0 x 10-13 1.0 x 10-14

0.010M strong acid

1.0 x 10-2 1.0 x 10-12 1.0 x 10-14

0.10M strong base 1.0 x 10-13 1.0 x 10-1 1.0 x 10-14

0.010M strong base

1.0 x 10-12 1.0 x 10-2 1.0 x 10-14

0.025M strong acid

2.5 x 10-2 4.0 x 10-13 1.0 x 10-14

0.025M strong base

4.0 x 10-13 2.5 x 10-2 1.0 x 10-14

pHpH

KC 13: pH is based on the concentration of hydronium (H3O) (hydrogen, H+) ions

KC 14: pH = -log[H3O+] (pH = -log[H+])

KC 15: pOH is based on the concentration of hydroxide (OH) ions

KC 16: pOH = -log[OH]

KC 13: pH is based on the concentration of hydronium (H3O) (hydrogen, H+) ions

KC 14: pH = -log[H3O+] (pH = -log[H+])

KC 15: pOH is based on the concentration of hydroxide (OH) ions

KC 16: pOH = -log[OH]

pHpH

KC 17: pH + pOH = 14

pH < 7 = acid

pH > 7 = base

pH = 7 = neutral

[H+] [OH-] = 1.0 x 10-14

KC 17: pH + pOH = 14

pH < 7 = acid

pH > 7 = base

pH = 7 = neutral

[H+] [OH-] = 1.0 x 10-14

pOH scale:pOH scale:

pOH

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

pH

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

[OH] = 1.0x10-14 /

[H+]

[H+] = 1.0x10-14 /

[OH-]

pOH= 14 - pH

pH = 14 - pOH

[H+]

= 1

0-p

H

pH

= -

log

[H+]

[H+] [OH-]

pH pOH

[OH

- ] =

10

-pO

H

pO

H =

-lo

g[O

H-]

PH/pOH to concentration conversion

flowchart

Calculating pH/pOHCalculating pH/pOH

Example – calculate the pH of a solution containing 3 mol of HCl dissolved in 400mL of water.

Example – calculate the pH of a solution containing 3 mol of HCl dissolved in 400mL of water.

Calculating pH/pOHCalculating pH/pOH

KC 18: A solution has a hydronium ion concentration of 6.7 x 10-1M, what is its pH?

KC 18: A solution has a hydronium ion concentration of 6.7 x 10-1M, what is its pH?

Calculation PracticeCalculation Practice

KC 19: If the hydronium ion concentration of a solution is 1.63 x 10-8M, what is the hydroxide ion concentration?

KC 19: If the hydronium ion concentration of a solution is 1.63 x 10-8M, what is the hydroxide ion concentration?

Reactions Between Acids and BasesReactions Between Acids and Bases

Key Concept 20: A neutralization reaction is a reaction in which an acid and a base in an aqueous solution react to produce salt and water.

Key Concept 21: A salt is an ionic compound made up of a cation from a base and an anion from an acid.

Composed of the negative ion of an acid and the positive ion of a base.

Key Concept 22: Neutralization is a double-replacement reaction.

Key Concept 20: A neutralization reaction is a reaction in which an acid and a base in an aqueous solution react to produce salt and water.

Key Concept 21: A salt is an ionic compound made up of a cation from a base and an anion from an acid.

Composed of the negative ion of an acid and the positive ion of a base.

Key Concept 22: Neutralization is a double-replacement reaction.

Reactions Between Acids and BasesReactions Between Acids and Bases

A neutralization reaction is the reaction an acid with a base to produce salt and water

HCl + NaOH → NaCl + H2O

2 NaOH + H2SO4 → 2 H2O + Na2SO4

A neutralization reaction is the reaction an acid with a base to produce salt and water

HCl + NaOH → NaCl + H2O

2 NaOH + H2SO4 → 2 H2O + Na2SO4

Predicting Acid/Base ReactionsPredicting Acid/Base Reactions

KC 23: Predict the products of the following reactions:

NaOH + H3PO4 →

KOH + HF →

H2SO4 + LiOH →

KC 23: Predict the products of the following reactions:

NaOH + H3PO4 →

KOH + HF →

H2SO4 + LiOH →

Beaker Indicator Basic Color Acidic ColorpH

Range

1Universal Indicator

 purple orange  10 to 4

2Bromcresol

green blue yellow-green

5.4 to 3.8

3 Methyl Red yellow  Red6.2 to

4.4

4Bromthymol

Blueblue  Yellow

7.6 to 6.0

Neutralization ReactionsNeutralization Reactions

KC 24: M1V1 = M2V2 can be used to calculate the volume and/or concentrations of neutralization reactions

KC 25: If 50.0mL of 1.00M HI is neutralizaed by 35.41mL of KOH, what is the molarity of the KOH solution?

KC 24: M1V1 = M2V2 can be used to calculate the volume and/or concentrations of neutralization reactions

KC 25: If 50.0mL of 1.00M HI is neutralizaed by 35.41mL of KOH, what is the molarity of the KOH solution?

Neutralization ReactionsNeutralization Reactions

KC 26: Titrations are a lab technique used to experimentally find and calculate the concentration of an unknown acid or base

KC 26: Titrations are a lab technique used to experimentally find and calculate the concentration of an unknown acid or base

TitrationsTitrations

The volume of base added can then be graphed versus the pH to determine the equivalence point

The concentration of the acid can then be determined from M1V1 = M2V2

The volume of base added can then be graphed versus the pH to determine the equivalence point

The concentration of the acid can then be determined from M1V1 = M2V2

TitrationsTitrations

KC 27: What is the molarity of sodium hydroxide if 20.0 ml of solution is neutralized by 28.0 ml of a 1.00 M solution of hydrochloric acid?

KC 27: What is the molarity of sodium hydroxide if 20.0 ml of solution is neutralized by 28.0 ml of a 1.00 M solution of hydrochloric acid?

TitrationsTitrations

KC 28: A base is reacted with an acid at a 1:1 ratio. If it took 23.5 mL of acid to react completely with 45.2 mL of 2.4M base what is the concentration of the acid?

KC 28: A base is reacted with an acid at a 1:1 ratio. If it took 23.5 mL of acid to react completely with 45.2 mL of 2.4M base what is the concentration of the acid?

TitrationsTitrations

video video