brn – place these items in the t-chart acidneutralbase
TRANSCRIPT
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?
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+]
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?
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 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
[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?