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Chemistry Chemistry Acid//Base Acid//Base Chemistry Chemistry

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Page 1: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

ChemistryChemistry

Acid//Base ChemistryAcid//Base Chemistry

Page 2: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

I. IntroductionI. Introduction

We’ve learned about:We’ve learned about:

- formation- formation

- decomposition- decomposition

- combustion- combustion

Now, we will learn about acid/base reactionsNow, we will learn about acid/base reactions

Page 3: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

II. Acids & BasesII. Acids & Bases

A. What is an acid?A. What is an acid?

1. Release a hydrogen ion (H1. Release a hydrogen ion (H++) in water (conduct ) in water (conduct electricity when added Helectricity when added H22O)O)

2. Neutralize bases in a neutralization rxn2. Neutralize bases in a neutralization rxn

3. Corrode active metals (releasing H3. Corrode active metals (releasing H2 2 gas)gas)

4. Turn blue litmus paper red4. Turn blue litmus paper red

5. Taste sour5. Taste sour

Page 4: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Notes on the properties of Notes on the properties of acids…acids…

Don’t taste!Don’t taste!

Conduct electricity Conduct electricity – – ionic compounds conduct electricityionic compounds conduct electricity-- Acids are special covalent compounds that conduct -- Acids are special covalent compounds that conduct electricity when added to Helectricity when added to H22O O

LitmusLitmus--an indicator--an indicator

IndicatorIndicator: a substance that turns one color in the presence of : a substance that turns one color in the presence of acids and another color in the presence of bases acids and another color in the presence of bases

Page 5: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Most acids are weak acids Most acids are weak acids (dissociate poorly)(dissociate poorly)

6 strong acids to memorize: 6 strong acids to memorize: Strong acids dissociate Strong acids dissociate completelycompletely in water (H in water (H++ + + ____--))

HClHCl HBrHBr HIHI

HNOHNO33

HClOHClO44

HH22SOSO44

Everything else is weak!Everything else is weak!

Page 6: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Acetic v. HClAcetic v. HCl

Page 7: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

B. What is a base?B. What is a base?

1. Release hydroxide ion in water1. Release hydroxide ion in water

2. Neutralize acids in neutralization rxns2. Neutralize acids in neutralization rxns

3. Denature proteins (feel slippery to the 3. Denature proteins (feel slippery to the touch)touch)

4. Bases turn red litmus paper blue4. Bases turn red litmus paper blue

5. Taste bitter (Do NOT taste!)5. Taste bitter (Do NOT taste!)

Page 8: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions
Page 9: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Strong bases to memorize:Strong bases to memorize:

-- Easy: the hydroxides of the alkali metals -- Easy: the hydroxides of the alkali metals and barium (alkaline earth metal)and barium (alkaline earth metal)

LiOHLiOH NaOHNaOH KOHKOH RbOHRbOH

CsOHCsOH Ba(OH)Ba(OH)22

Page 10: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

III. The Chemical Definition III. The Chemical Definition of Acids and Basesof Acids and Bases

Acid: a molecule that donates HAcid: a molecule that donates H++ ion(s) ion(s)

Bases: a molecule that accepts HBases: a molecule that accepts H+ + ion(s)ion(s)

For example:For example:

HCl + HHCl + H22O → HO → H33OO++ + Cl + Cl--

Which is the acid and which is the base?Which is the acid and which is the base?

Page 11: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Important note about HImportant note about H33OO++

-- Called the hydronium ion-- Called the hydronium ion

-- Most often written as H-- Most often written as H++

-- As H-- As H++, just referred to as H, just referred to as H++, hydrogen , hydrogen ion, or a protonion, or a proton

-- H-- H33OO+ + and H and H++ are the really the same are the really the same

thing and are used interchangeablything and are used interchangeably

Page 12: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions
Page 13: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Another acid/base reaction:Another acid/base reaction:

HH22O(l) + NHO(l) + NH33(aq) → NH(aq) → NH44++(aq) + OH(aq) + OH--

Which is the acid and which is the base?Which is the acid and which is the base?

Water can be Water can be bothboth an acid or a base – an acid or a base – depending on what it reacts withdepending on what it reacts with

Amphiprotic compoundsAmphiprotic compounds: Compounds that can : Compounds that can act as either an acid or a baseact as either an acid or a base

Page 14: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Examples:Examples:

Which is acid and which is base?Which is acid and which is base?

HH22SOSO44(aq) + CaCO(aq) + CaCO33(aq) →(aq) →

CaCa2+2+(aq) + HSO(aq) + HSO44--(aq) + HCO(aq) + HCO33

--(aq)(aq)

HCl(aq) + NaOH(aq)→HHCl(aq) + NaOH(aq)→H22O(l) + NaCl(aq)O(l) + NaCl(aq)

2HNO2HNO33(aq) + Mg(OH)(aq) + Mg(OH)22(aq) →(aq) →

Mg(NOMg(NO33))22(aq) + 2H(aq) + 2H22O(l)O(l)

Page 15: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

OYO’sOYO’s

Determine the acid and base in the Determine the acid and base in the following reactions:following reactions:

10.1 HBr(aq) +NH10.1 HBr(aq) +NH33(aq)(aq)→NH→NH44++(aq) (aq)

+ Br + Br --(aq)(aq)

10.2 3C10.2 3C22HH44OO22(aq) +Al(OH)(aq) +Al(OH)3 3 →→

Al(CAl(C22HH33OO22))33(aq) + 3H(aq) + 3H22O(l)O(l)

Page 16: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

10.3 H10.3 H33POPO44(aq) + 3KOH(aq) →(aq) + 3KOH(aq) →

3H3H22O(l) + KO(l) + K33POPO44(aq)(aq)

Page 17: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

IV. Recognizing and Naming IV. Recognizing and Naming Acids and Bases from their Acids and Bases from their FormulasFormulasA. Recognizing - General Trends (not A. Recognizing - General Trends (not

strictly true):strictly true):-- Acids start with “H” in the formula-- Acids start with “H” in the formula

except Cexcept C22HH44OO2 2 (aka CH(aka CH33COOH and COOH and HCHC22HH33OO22))

-- Bases that are ionic compounds and -- Bases that are ionic compounds and have have ““OH” in formulaOH” in formula

(2 notable exceptions: H(2 notable exceptions: H22O and NHO and NH33))

Page 18: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Acid, base, or neither?:Acid, base, or neither?:

HFHF

CHCH44

RbOHRbOH

CHCH33OHOH

HNOHNO33

HH22SOSO44

NaOHNaOH

Page 19: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

B. Naming acids and basesB. Naming acids and bases1. Acids1. Acids

-- ions that end in “-ide”-- ions that end in “-ide”hydro______ic acid (e.g., HCl)hydro______ic acid (e.g., HCl)

-- ions that end in “-ate”-- ions that end in “-ate”

__________ic acid (e.g., H__________ic acid (e.g., H22SOSO44))

-- ions that end in “-ite”-- ions that end in “-ite”

__________ous acid (e.g., HNO__________ous acid (e.g., HNO22))

2. Bases2. Bases-- Normal ionic naming rules-- Normal ionic naming rules

(e.g., Sr(OH)(e.g., Sr(OH)22 – strontium hydroxide) – strontium hydroxide)

Page 20: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

V. Predicting the Reactions that V. Predicting the Reactions that Occur between Acids and BasesOccur between Acids and Bases

A. How many protons can an acid donateA. How many protons can an acid donate

HH33POPO44 can donate up to 3 H can donate up to 3 H++

-- “more than one” – “proton”-- “more than one” – “proton”Polyprotic acidPolyprotic acid: An acid that can donate more : An acid that can donate more than one protonthan one protonTriprotic acidTriprotic acid: An acid that can donate up to 3 : An acid that can donate up to 3 protonsprotonsDiprotic acidDiprotic acid: An acid that can donate up to 2 : An acid that can donate up to 2 protonsprotons

Page 21: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

B. Acids and Ionic BasesB. Acids and Ionic Bases

Hydrofluoric acid and potassium hydroxideHydrofluoric acid and potassium hydroxide

HF + KOH → ?HF + KOH → ?Steps to solving:Steps to solving:

1. Write acid and base as individual ions1. Write acid and base as individual ions2. Combine the negative acid ion with the 2. Combine the negative acid ion with the positive base ion, put the Hpositive base ion, put the H++ with the negative with the negative base ionbase ion3. Balance (if necessary)3. Balance (if necessary)

Page 22: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Acid + Ionic base → Salt + waterAcid + Ionic base → Salt + water

HCl + NaOH → NaCl + HHCl + NaOH → NaCl + H22OO

(You think of “salt” and NaCl – but a salt is (You think of “salt” and NaCl – but a salt is any ionic compound that formed because any ionic compound that formed because an ionic base reacted with an acid!)an ionic base reacted with an acid!)

Page 23: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions
Page 24: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions
Page 25: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Examples:Examples:

Hydrochloric acid and rubidium hydroxideHydrochloric acid and rubidium hydroxide

Sulfuric acid and sodium hydroxideSulfuric acid and sodium hydroxide

Nitric acid and aluminum hydroxideNitric acid and aluminum hydroxide

Page 26: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

OYO’sOYO’s10.4 Give the chemical equation that 10.4 Give the chemical equation that

represents the reaction between each of represents the reaction between each of the following:the following:

a. HClOa. HClO33 and KOH and KOH

b. HBr and Ca(OH)b. HBr and Ca(OH)22

c. Hc. H33POPO44 and Mg(OH) and Mg(OH)22

Page 27: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Everyday example of acids and Everyday example of acids and bases:bases:

Drain uncloggers contain baseDrain uncloggers contain base ;;-- proteins contain amino acids (hair, food)-- proteins contain amino acids (hair, food)

Acid + Ionic base→ Salt + waterAcid + Ionic base→ Salt + water

All-purpose Cleaners contain basesAll-purpose Cleaners contain bases-- most spills are acidic-- most spills are acidic

Toilet bowl cleaners (contain acid)Toilet bowl cleaners (contain acid)--lime stains (CaO) are a common problem--lime stains (CaO) are a common problem-- CaO reacts with water in toilet to become CaOH-- CaO reacts with water in toilet to become CaOH-- acid neutralizes-- acid neutralizes

Page 28: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

B. Acids and Covalent BasesB. Acids and Covalent BasesSo…Acid + Ionic Base → Salt + waterSo…Acid + Ionic Base → Salt + water

……but when an acid is reacts with a but when an acid is reacts with a covalent base (and it always does – because covalent base (and it always does – because it is in aqueous solution) –it is in aqueous solution) –

ions resultions result

HH22SOSO44 + H + H22O → 2HO → 2H33OO++ + SO + SO442-2-

Acid + Covalent Base → ionsAcid + Covalent Base → ions

Page 29: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Examples:Examples:

HH33POPO44 + 3NH + 3NH33 → →

3NH3NH44++ + PO + PO44

3-3-

HOCl + HHOCl + H22O → O →

HH33OO++ + ClO + ClO--

Page 30: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

OYO’sOYO’s10.5 What is the chemical equation that 10.5 What is the chemical equation that

describes the reaction between Hdescribes the reaction between H22SOSO44 and and

ammonia (NHammonia (NH33)?)?

10.6 What reaction occurs between HI and 10.6 What reaction occurs between HI and water?water?

Page 31: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

V. Molarity V. Molarity (a.k.a. concentration)(a.k.a. concentration)

Density = g/mLDensity = g/mL

Concentration in Chemistry:Concentration in Chemistry:

moles/L = Molarity (moles/L = Molarity (MM))

Page 32: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Example: Example: The WorksThe Works is 3% HCl; is 3% HCl; muriatic muriatic acid acid is 30% HClis 30% HCl

What is the What is the MM of 1400.0 grams of muriatic of 1400.0 grams of muriatic acid in 4.00 L of water?acid in 4.00 L of water?

What is the What is the MM of HCl in of HCl in The WorksThe Works??

Page 33: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

More Examples:More Examples:

What is the What is the MM of NaOH when 2.6 moles of of NaOH when 2.6 moles of NaOH are dissolved in 534 mL?NaOH are dissolved in 534 mL?

124.3 g of HNO124.3 g of HNO33 are dissolved in 250.0mL. are dissolved in 250.0mL.

What is the What is the MM??

Page 34: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

OYO’sOYO’s10.7 Determine the concentration for the 10.7 Determine the concentration for the

following acids and bases:following acids and bases:

A. 2.1 moles HCl in 346 mL solutionA. 2.1 moles HCl in 346 mL solution

B. 6.78 g KOH in 150.0 mLB. 6.78 g KOH in 150.0 mL

C. 20.1 g HC. 20.1 g H22SOSO44 in 3.4 L in 3.4 L

Page 35: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

VI. DilutionVI. Dilution

Chemists don’t usually measure grams of acid or Chemists don’t usually measure grams of acid or base solution to make certain concentrations…base solution to make certain concentrations…

They dilute! (Always add They dilute! (Always add acid TO acid TO water – if you water – if you add water to acid, the acid may splash on you)add water to acid, the acid may splash on you)

Here’s the formula (memorize):Here’s the formula (memorize):

CC11VV1 1 = C= C22VV22

Page 36: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

CC11 = = MM of thing you are diluting of thing you are diluting

VV11 = Volume of initial thing (how much of it = Volume of initial thing (how much of it you will use (can be in mL or L – as long as you will use (can be in mL or L – as long as VV22 is measured in the same units) is measured in the same units)

CC22 = = MM you want in the end you want in the end

VV22 = Final volume of new concentration = Final volume of new concentration (important: this is V(important: this is V11 + water to get to V + water to get to V22))

water you add = Vwater you add = V22 – V – V11

Page 37: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Examples:Examples:

Chemist wants to dilute 12.0Chemist wants to dilute 12.0MM HCl to get HCl to get 500 mL of 3.5500 mL of 3.5MM HCl solution HCl solution

Chemist makes 2.4L of 5.6Chemist makes 2.4L of 5.6MM NaOH and NaOH and adds water to 10.0 L. New concentration?adds water to 10.0 L. New concentration?

Dilution equation not only applies to acids Dilution equation not only applies to acids and bases, but to and bases, but to allall chemicals! chemicals!

Page 38: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

OYOOYO

10.8 Chemist needs 750.0 mL of 3.510.8 Chemist needs 750.0 mL of 3.5MM HH22SOSO44. Has 10.0. Has 10.0MM H H22SOSO44. Write out how . Write out how

you would do the dilution.you would do the dilution.

Page 39: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

VII. Using Concentration in VII. Using Concentration in StoichiometryStoichiometry

You can use the You can use the MM of an acid or base to of an acid or base to find out how many grams of productfind out how many grams of product

2HCl +2HCl + Ba(OH)Ba(OH)22 → → BaClBaCl22 + +

2H2H22OO

101000 mL mL excess excess ? g? g

6.186.18MM

Page 40: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

Example:Example:

Sodium sulfate can be made by reacting Sodium sulfate can be made by reacting HH22SOSO44 with sodium hydroxide. How many with sodium hydroxide. How many

grams of sodium sulfate can be produced grams of sodium sulfate can be produced if 500.0 mL of 1.6if 500.0 mL of 1.6MM sodium hydroxide is sodium hydroxide is reacted with excess sulfuric acid?reacted with excess sulfuric acid?

Page 41: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

OYOOYO10.9 Barium hydroxide is often used to clean 10.9 Barium hydroxide is often used to clean

up toxic acid spills in industrial settings. If up toxic acid spills in industrial settings. If 10.0 L container of 12.0 10.0 L container of 12.0 MM nitric acid is nitric acid is broken, how many grams of barium broken, how many grams of barium hydroxide will be needed to clean up the hydroxide will be needed to clean up the spill?spill?

Page 42: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

VIII. Acid/Base TitrationsVIII. Acid/Base Titrations

TitrationTitration: The process of slowly reacting a : The process of slowly reacting a base of unknown concentration with an base of unknown concentration with an acid of known concentration (or vice acid of known concentration (or vice versa) until just enough acid has been versa) until just enough acid has been added to react with all of the base (the added to react with all of the base (the endpointendpoint has been reached). has been reached).

Just stoichiometry with acids and bases!Just stoichiometry with acids and bases!

Page 43: Chemistry Acid//Base Chemistry. I. Introduction We’ve learned about: - formation - decomposition - combustion Now, we will learn about acid/base reactions

OYOOYO

10.10 125mL of nitric acid with unknown 10.10 125mL of nitric acid with unknown MM is titrated against magnesium hydroxide is titrated against magnesium hydroxide with a concentration of 2.3 with a concentration of 2.3 MM. If 35.4 mL . If 35.4 mL of base are required in order to reach the of base are required in order to reach the endpoint, what was the concentration of endpoint, what was the concentration of the acid?the acid?