Acids, Bases and Salts.pptx

Acids, Bases and Salts

Ch-3

Continue

Contents

• Acids• Bases• Salts• Indicators

End Show

Acids• Definitions• Classification• Arrhenius and Lowry-Bronsted’s Theory• Hydronium Ions from Acids• Preparation• Physical Properties• Chemical Properties• Uses

Contents

Definitions

Acids: It is a chemical compound containing one or more replaceable hydrogen ions which are completely or partially replaced by a metallic element or a group of elements acting as a metal to produce salt

Basicity of Acid:It s the number of replaceable hydrogen atoms present in one molecule of an acid.

Hydracid:It is an acid containing hydrogen atoms and an electronegative element other than oxygen is known as hydracid.

Oxyacid:It is an acid containing hydrogen atoms and oxygen atoms is known as oxyacid.

Heat of Neutralization:The amount of heat released when 1 gram equivalent of an acid and a base is completely neutralized is known as heat of neutralization.

Contents Acids

Next

DefinitionsStrong Acids: An acid which is completely ionized into its constituent ions when dissolved in water (α>30%) thereby producing large concentration of H+ ions in the solution is known as strong acid.

Weak Acids:An acid which is partially ionized into its constituent ions when dissolved in water (α<30%) thereby producing small concentration of H+ ions in the solution is known as weak acid.

Concentrated Acid:It is an acid containing more acid than water in its aqueous solution.

Dilute Acid:It is an acid containing less acid than water in its aqueous solution. [less than 1 mole/litre]

Contents Acids Previous

Classification• On Basis of Source:

– Organic Acids – Derived from plants– Inorganic Acids - Derived from minerals

• On Basis of Molecular Composition of Acids:– Hydracids – HCl, HBr, HI, etc.– Oxyacids – HNO 3 , H 2 SO 4 ,etc.

• On Basis of Strength of Acids:Depends on concentration of hydronium ions present in an aqueous solution of an acid.– Strong Acid – HNO3 , H2SO4 , HCl [Contains only ions]

– Weak Acid – CH3COOH, Acetic*, Citric, Carbonic and Formic Acid [Contains molecules and ions]

• On Basis of Concentration of Acids:– Concentrated Acid– Dilute Acid

• On Basis of Basicity of Acids:– Monobasic Acid – produces one hydrogen ion per molecule of the acid, forming one type

of salt. Ex. HCl, HI, HBr, HNO3, CH3COOH#, etc.

– Dibasic Acid – produces two hydrogen ion per molecule of the acid, forming an acid salt and a normal salt. Ex. H2SO4, H2CO3, H2SO3 , etc.

– Tribasic Acid – produces three hydrogen ion per molecule of the acid, forming two acid salts and a normal salt. Ex. H3PO4, etc.

Contents Acids

* - Anhydrous acetic acid on cooling forms crystals of glacial acetic acid

# - Acetic Acid has four hydrogen atoms in it, but ionizes in aqueous solution to produce one hydrogen ion per molecule of the acid

Arrhenius and Lowry-Bronsted’s TheoryArrhenius Theory: Acids are substances which dissociate in aqueous solution to give H+ ions. Strong acids dissociate almost completely while weak acids dissociate partially.

Lowry-Bronsted’s Theory: Acids are proton donors.• HCl H+ + Cl-

Contents Acids

Hydronium Ions from AcidsReaction:

Contents Acids

Next

WATER MOLECULE2 Lone pairs of Electrons

Hydronium Ions from AcidsThe Water Molecule:•Water is a polar covalent molecule and exhibits charge separation.•The H atom of water carries a slight positive charge and the O atom a slight negative charge.•Oxygen atom in water have two lone pairs of electrons not shared with any other atom.•A proton i.e. H+ ion released from the acid adds on to the lone pair of electrons of the oxygen atom of the water molecule [oxygen atom in H2O has a slight negative charge].•The H+ ion accepts the lone pair of electrons forming a coordinate covalent

bond [ O H ]

Contents Acids Previous

PreparationFrom Non-Metals: Hydrogen + Non-Metal (halogen) Acid •

H2 + Cl2 2HCl

• H2 + I2 2HI

From Acidic Oxides: Acidic Oxide+ Water Acid• CO2 + H2O H2CO3

• SO2 + H2O H2SO3

• SO3 + H2O H2SO4

• P2O5 + H2O H3PO4

From Salts: Normal Salt + Sulphuric Acid (conc.) Acid Salt + Displaced Volatile Salt• KNO3 + H2SO4 KHSO4 + HNO3

• NaCl + H2SO4 NaHSO4 + HCl

By Oxidation of Non-Metals:Sulphur + Nitric Acid Sulphuric Acid + Water + Nitrogen Dioxide• S + 6HNO3 H2SO4 + 2H2O + 6NO2

Contents Acids

<200°C

<200°C

Physical Properties

Sour in taste in aqueous solution

Highly Corrosive: Mineral Acids (H2SO4, HNO3, HCl)

Action on Indicators:

Contents Acids

Litmus

Methyl Orange

Phenolphthalein

Phenolphthalein (alkaline)

Red

Pink

Colourless

Colourless

Litmus (Alkaline) Red

Methyl Orange (alkaline)

Pink

Chemical Properties Test for Hydronium Ions

Neutralization Reaction: Acid + Base Salt + Water •

CuO + H2SO4 CuSO4 + H2O

• NaOH + HCl NaCl + H2O

Reaction of Active Metals with Acids: Active Metal + Acid (dil.) Salt + Hydrogen• Zn + 2HCl ZnCl2 + H2

Reactions of Chlorides, Nitrates, Bicarbonates and Carbonates with Acid: Salt [1] + Less Volatile Acid [1] Salt [2] + More Volatile Acid [2]• NaNO3 + H2SO4 (conc.) KHSO4 + HNO3

• NaCl + H2SO4 (conc.) NaHSO4 + HCl

• 2NaHCO3 + H2SO4 (dil.) Na2SO4 + 2H2O + 2CO2

• Na2CO3 + 2HCl (dil.) NaCl + H2O + CO2

Contents Acids

<200°C

<200°C

unstable H2CO3

formed

H+ [aq.] + OH- [aq.] H2O [l]

Uses1. Eye-Wash - Boric acid

2. Food preservation - Citric Acid

3. Ink-Stain Remover - Oxalic Acid

4. Flavouring Drinks - Carbonic Acid

5. Baking Powder - Tartaric Acid

6. Cooking - Acetic Acid [ vinegar ]

7. Pickling of Metals - Hydrochloric Acid (HCl)

Contents Acids

Bases• Definitions• Classification• Arrhenius and Lowry-Bronsted’s Theory• Hydroxyl Ions from Alkali• Preparation• Physical Properties• Chemical Properties• Uses

Contents

Definitions

Bases: Metallic oxides and hydroxides which on reaction with acids produce salt and water as the only products are known as bases.

Acidity of Base:It s the number of replaceable hydroxyl ions produced per molecule of a base when it is dissolved in water.

Heat of Neutralization:The amount of heat released when 1 gram equivalent of an acid and a base is completely neutralized is known as heat of neutralization.

Contents

Next

Bases

Definitions

Strong Base: A base which is completely ionized into its constituent ions when dissolved in water (α>30%) thereby producing large concentration of OH- ions in the solution is known as strong base.

Weak Base:An base which is partially ionized into its constituent ions when dissolved in water (α<30%) thereby producing small concentration of OH- ions in the solution is known as weak base.

Concentrated Alkali:It is an acid containing more alkali than water in its aqueous solution.

Dilute Alkali:It is an acid containing less alkali than water in its aqueous solution [less than 1 mole/litre].

Contents PreviousBases

Classification• On Basis of Strength of Bases:

Depends on concentration of hydroxyl ions present in an aqueous solution of an alkali.– Strong Alkali – NaOH, KOH, LiOH [Contains solute molecules in addition to water

molecules]– Weak Alkali – NH4OH, Ca(OH)2 [Contains molecules and ions]

• On Basis of Concentration of Acids:– Concentrated Alkali– Dilute Alkali

• On Basis of Acidity of Bases:– Monoacidic Base – produces one hydroxyl ion per molecule of the water-soluble base,

dissociating in one step in aqueous solution. Ex. NaOH, KOH, etc.– Diacidic Base – produces two hydroxyl ion per molecule of the water-soluble base,

dissociating in one step in aqueous solution. Ex. Ca(OH)2, Zn(OH)2, etc.

– Triacidic Base – produces three hydroxyl ion per molecule of the water-soluble base, dissociating in one step in aqueous solution. Ex. Al(OH)3, Fe(OH)3, etc.

Contents Bases

Arrhenius and Lowry-Bronsted’s TheoryArrhenius Theory: Bases are substances which dissociate in aqueous solution to give OH- ions. Strong bases dissociate almost completely while weak bases dissociate partially.

Lowry-Bronsted’s Theory: Bases are proton acceptors.• NH3 + H+ NH4

+

Contents Bases

Hydroxyl Ions from AlkaliReaction:

Contents

Next

Bases

Hydroxyl Ions from AlkaliThe Water Molecule:•Water is a polar covalent molecule and exhibits charge separation.•The H atom of water carries a slight positive charge and the O atom a slight negative charge.•Oxygen atom in water have two lone pairs of electrons not shared with any other atom.•A proton i.e. H+ ion released from the water adds on to the lone pair of electrons of the nitrogen atom of the ammonia molecule [ nitrogen atom in NH3 has a slight negative charge ].

•The H+ ion accepts the lone pair of electrons forming a coordinate covalent

bond [ N H ]

Contents PreviousBases

[ Ammonia is a polar covalent compound with a large difference in electronegativity between the nitrogen atom and the hydrogen atoms in the ammonia molecule ]

PreparationFrom Metals: Hydrogen + Oxygen Base [Basic Oxide] •

4Na + O2 2Na2O

• 2Mg + O2 2MgO

From Basic Oxides: Basic Oxide+ Water Base• K2O + H2O 2KOH

• Na2O + H2O NaOH

From Salts: Salt soln. + Alkali Normal Salt + ppt. Basic Hydroxide • AlCl3 + 3NaOH 3NaCl + Al(OH)3

• FeSO4 + NaOH Na2SO4 + Fe(OH)2

By Decomposition of Salts:2PbNO3 2PbO + O2 + 4NO2

2ZnNO3 2ZnO + O2 + 4NO2

2CuNO3 2CuO + O2 + 4NO2

Contents Bases

Physical Properties

Bitter in taste in aqueous solution

Highly Corrosive: Caustic Alkalis (KOH, NaOH)

Action on Indicators:

Contents

Litmus

Methyl Orange

Phenolphthalein

Phenolphthalein (alkaline)

Blue

Yellow

Colourless

Colourless

Litmus (Alkaline) Blue

Methyl Orange (alkaline)

Yellow

Bases

Chemical Properties Test for Hydroxyl Ions

Neutralization Reaction: Acid + Base Salt + Water •

CuO + H2SO4 CuSO4 + H2O

• NaOH + HCl NaCl + H2O

Alkalis react with Ammonium Salts to Liberate Ammonia: Ammonium Salt + Base [1] Salt [2] + Base [2]• NH4Cl + 2NaOH NaCl + NH3 + H2O

Reactions with certain metallic salt solutions: Metallic Salt + Base [aq.] Salt [2] + Insoluble Hydroxide• CuCl2 + 2NaOH 2NaCl + Cu(OH)2

• FeCl3+ 3NaOH 3NaCl + Fe(OH)3

• ZnSO4 + 2NaOH Na2SO4 + Zn(OH)2

Contents

Blue ppt.Red brown ppt.Gelatinous White ppt.

H+ [aq.] + OH- [aq.] H2O [l]

Bases

NH4OH

Uses1. Manufacture of Soaps - NaOH

2. Manufacture of Bleaching Powder - Ca(OH)2

3. As an Antacid [to neutralize acidity] - Mg(OH)2

4. As a foaming agent in fire extinguishers - Al(OH)3

5. In Softening Water - Ca(OH)2

6. In Removing Grease Stains from Clothes - NH4OH

Contents Bases

Salts• Definitions• Classification• Solubility of Salts• General Methods of Preparation• Hydrolysis

Contents

Epsom Salt

Definitions

Salts: A chemical compound formed by complete or partial displacement of the replaceable H+ ions of an acid by a metal or a group of elements acting as a metal is known as a salt.

Normal Salt:It is a chemical compound formed by the complete neutralization between an acid and a base.

Acid Salt:It is a chemical compound formed by the partial or incomplete neutralization of an acid by a base.

Basic Salt:It is a chemical compound formed by the partial or incomplete neutralization of a base by an acid.

Contents

Next

Salts

Definitions

Double Salt: It is a chemical compound formed by the mixing of two normal salts in molecular proportion followed by crystallization from their hot saturated solution.

Complex Salt:It is a chemical compound formed by the mixing of two salts in molecular proportion followed by crystallization from their hot saturated solution such that when the salt is dissolved in water a simple and a complex ion is formed.

Water of Crystallization:It is the definite number of water molecules that are in a loose chemical association with one molecule of a certain salt, responsible for its crystalline structure, and formed by the crystallization of their hot saturated solution.

Contents PreviousSalts

Next

Definitions

Efflorescence: It is a phenomenon due to which certain hydrated crystalline salt when exposed to open atmosphere lose their water of crystallization completely or partially thereby converting to a solid amorphous powdered residue.

Deliquescence:It is a phenomenon due to which certain crystalline salt when exposed to open atmosphere absorb moisture from it thereby going into a liquid state.

Hydrolysis:It is a type of reaction whereby a salt when dissolved in water will partially dissociate to form the parent acid and the parent base.

Contents PreviousSalts

EfflorescenceDeliquescent substance

Classification• Acid Salt: NaHSO4, NaH2PO4, etc.

• Normal Salt: Na2SO4, Cu(OH)2, etc.

• Basic Salt: Cu[OH]NO3 (Basic copper nitrate), Cu[OH]Cl (Basic copper chloride)• Double Salt: Alum (K2SO4.Al2(SO4)3.24H2O), Mohr Salt (FeSO4.(NH4)2SO4.6H2O)

• Mixed Salt: NaKCO3, Bleaching Powder (Ca(OCl)Cl)

• Complex Salt: Nesseler’s Reagent (K2[HgI4]), Na2ZnO2

Contents Salts

Solubility Chart

Contents Salts

All Na+, K+, NH4+ Salts -

Soluble Insoluble

* - PbCl2 soluble in hot water

All NO3-, NO2

- Salts -

All HCO3- Salts KHCO3, NaHCO3

All SO42- Salts PbSO4

, AgSO4 , CaSO4

, BaSO4

All Cl- Salts PbCl2 *, AgCl, HgCl

- All SO3- Salts

- All S2- Salts

- All CO3- Salts

- All O2- Salts

- All OH- Salts

- All PO43- Salts

General Methods of Preparation

1. Preparation of Soluble Salts

2. Preparation of Insoluble Salts

Contents Salts

Preparation of Soluble Salts1. Neutralization

2. Neutralization using Titration

3. Displacement

4. Direct Combination

5. Decomposition of Carbonates/Bicarbonates

6. Decomposition of Chlorides

7. Decomposition of Nitrates

Contents General Methods of Preparation

NeutralizationReaction: Acid + Base Salt + Water •Insoluble Oxide + Acid

– CuO + H2SO4 CuSO4 + H2O

– PbO + 2HNO3 Pb(NO3)2 + H2O

– CaO + 2HCl CaCl2 + H2O

•Insoluble Hydroxide + Acid– Cu(OH)2 + 2HCl CuCl2 + 2H2O

– Pb(OH)2 + 2HCl PbCl2 + 2H2O

•Insoluble Carbonate/Bicarbonate + Acid–

CuCO3 + H2SO4 CuSO4 + CO2 + H2O

– NaHCO3 + HCl NaCl + CO2 + H2O

– PbCO3 + 2HNO3 Pb(NO3)2 + 2CO2 + 2H2O

– ZnCO3 + 2HNO3 Zn(NO3)2 + 2CO2 + 2H2O

Contents Preparation of Soluble Salts

Neutralization using TitrationReaction: Acid + Alkali Salt + Water •Soluble Hydroxide + Acid

– NaOH + HCl Na2SO4 + H2O

– KOH + HCl KCl + H2O

– 2NH4OH + H2SO4 (NH4)2SO4 + H2O

•Soluble Carbonate/Bicarbonate + Acid–

Na2CO3 + H2SO4 Na2SO4 + CO2 + H2O

– Ca(HCO3)2 + 2HNO3 Ca(NO3)2 + 2CO2 + 2H2O

– (NH4)2CO3 + 2HCl NH4Cl + 2CO2 + 2H2O

Contents Preparation of Soluble Salts

DisplacementReaction: Metal + Acid Salt + Hydrogen Gas• Zn + H2SO4 ZnSO4 + H2

• Zn + 2HCl ZnCl2 + H2

• Fe + H2SO4 FeSO4 + H2

• Fe + 2HCl FeCl2 + H2

• Mg + H2SO4 MgSO4 + H2

• Mg + 2HCl MgCl2 + H2

• Zn + CuSO4 ZnSO4 + Cu

• Fe + CuSO4 FeSO4 + Cu

Contents

[Pb + H2SO4 PbSO4 + H2

Above reaction is possible, but since PbSO4 is an insoluble salt, it will form a coating and the reaction will thereby stop.]

Preparation of Soluble Salts

Direct CombinationReaction: A + B AB• 2Fe + 3Cl2 2FeCl3• 2Al + 3Cl2 2AlCl3

Contents Preparation of Soluble Salts

Decomposition of Carbonates/BicarbonateReaction: Carbonate + Acid [dil.] Salt + Water + Carbon Dioxide•Soluble Carbonate/Bicarbonate + Acid [dil.]

– Na2CO3 + H2SO4 Na2SO4 + CO2 + H2O

– Ca(HCO3)2 + 2HNO3 Ca(NO3)2 + 2CO2 + 2H2O

– (NH4)2CO3 + 2HCl NH4Cl + 2CO2 + 2H2O

•Insoluble Carbonate/Bicarbonate + Acid [dil.]–

CuCO3 + H2SO4 CuSO4 + CO2 + H2O

– NaHCO3 + HCl NaCl + CO2 + H2O

– PbCO3 + 2HNO3 Pb(NO3)2 + 2CO2 + 2H2O

– ZnCO3 + 2HNO3 Zn(NO3)2 + 2CO2 + 2H2O

Contents Preparation of Soluble Salts

Decomposition of ChloridesReaction: Chloride Salt + Acid [1] [conc.] Salt + Hydrogen chloride [2] •NaCl + H2SO4[conc.] NaHSO4 + HCl

•NaCl + H2SO4[conc.] Na2SO4 + HCl

•KCl + H2SO4[conc.] KHSO4 + HCl

•KCl + H2SO4[conc.] K2SO4 + HCl

Contents

<200°C

<200°C

>200°C

>200°C

Preparation of Soluble Salts

Decomposition of NitratesReaction: Nitrate Salt + Acid [1] [conc.] Salt + Nitric Acid [2] •NaNO3 + H2SO4[conc.] NaHSO4 + HNO3

•NaNO3 + H2SO4[conc.] Na2SO4 + HNO3

•KNO3 + H2SO4[conc.] KHSO4 + HNO3

•KNO3 + H2SO4[conc.] K2SO4 + HNO3

Contents

<200°C

<200°C

>200°C

>200°C

Preparation of Soluble Salts

Preparation of Insoluble Salts1. Direct Combination

2. Double Decomposition (precipitation)

Contents General Methods of Preparation

Direct CombinationReaction: A + B AB• Fe + S FeS• Zn + S ZnS• Pb + S PbS• Cu + S CuS

Contents Preparation of Insoluble Salts

Double Decomposition (precipitation)Reaction: •Soluble Salt Solution + Acid [1] Insoluble Salt + Acid [2]

– AgNO3 + HCl AgCl + HNO3

– BaCl2 + H2SO4 BaSO4 + 2HCl

– Ca(NO3)2 + H2SO4 CaSO4 + 2HNO3

– Pb(NO3)2 + H2S PbS + 3HNO3

•Soluble Salt Solution [1] + Soluble Salt Solution [2] Soluble Salt + Precipitated Insoluble Salt

– Pb(NO3)2 + 2NaCl 2NaNO3 + PbCl2– CaCl2 + 2Na2CO3 2NaCl + CaCO3

– ZnSO4 + (NH4)2CO3 (NH4)2SO4 + ZnCO3

– Pb(NO3)2 + Na2SO4 2NaNO3 + PbSO4

Contents

Convert Insoluble Salt to Insoluble Salt

Preparation of Insoluble Salts

Insoluble Salt to Insoluble SaltReaction:

1. Insoluble Salt Solution + Acid Soluble Salt [1]

2. Soluble Salt Solution [1] + Soluble Salt Solution [2] Precipitated Insoluble Salt

Ex: • PbO PbCl2

– PbO + HNO3 Pb(NO3)2 + H2O

– Pb(NO3)2 + 2NaCl 2NaNO3 + PbCl2

• PbCO3 PbSO4

– 2HNO3 + 2PbCO3 Pb(NO3)2 + H2O + CO2

– Pb(NO3)2 + 2Na2SO4 2NaNO3 + PbSO4

Contents Double Decomposition (precipitation)

Hydrolysis

•NH4Cl + H2O NH4OH + HCl

•NaHCO3 + H2O NaOH + H2CO3

•Na2CO3 + H2O 2NaOH + H2CO3

•NaCl + H2O NaOH + HCl

•MgCl2 + 2H2O Mg(OH)2 + 2HCl

•NH4CO3 + H2O H2CO3 + NH4OH

Contents Salts

pH of Solution Reason

Acidic Strong Acid + Weak Base

Alkaline Strong Base +Weak Acid

Alkaline Strong Base + Weak Acid

Neutral Strong Base + Strong Acid

Acidic Strong Acid + Weak Base

Neutral Weak Base + Weak Acid

Indicators• Definitions• pH Value of a Medium• Determination of pH by Indicators• Types of Indicators• Difference Between Common Acid-Base Indicators and Universal Indicators• Colour Changes by Indicators• Utility of Indicators and pH Values• pH Values of Some Common Substances

Contents

Definitions

Indicators: Indicators are weak organic compounds [ acids or bases ] which change colour in accordance with the pH of the solution.

pH of a Solution:pH of a solution is the negative logarithm [to the base 10] of hydrogen ion concentration in the solution, expressed in moles/litre.

pH = log [ H+ ] ( [ H+ ] is the molar concentration)

pH Scale:It is a scale showing the relative strength of acids and alkalis.

Contents Indicators

pH Value of a Medium•Pure water is neutral and ionizes very slightly to yield equal number of hydrogen ions and hydroxyl ions.•The concentration of [H+] ions and [OH-] ions are both equal to 10-7 mol.dm-3 [at 25° C].•Thus the product of the two ionic concentrations is –

kW = ionic product of water = [H+][OH-] = 10-7x10-7 = 10-14 [at 25° C]• When an acid is added to the aqueous medium the [H+] ion concentration increases above 10-7 and at the same time the [OH-] ion concentration decreases to below 10-7.

Contents

pH 7 Neutral

pH less than 7 Acidic

pH more than 7 Basic

[H+ aq. ] = [OH-]

[H+ aq. ] > [OH-]

[H+] < [OH- aq. ]

Indicators

Determination of pH by Indicators

Contents Indicators

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Acidity increases Alkalinity increases

Neutral

Universal Indicator

pH Scale

Types of Indicators

There are two types of indicators:•Common Acid-Base Indicators•Universal Indicators

Contents Indicators

Difference Between Common Acid-Base Indicators and Universal Indicators

Contents Indicators

Common Acid-Base Indicators Universal Indicators

Indicates whether a solution is acidic or alkaline

Indicates the strength or pH range of the solution

Cannot be utilized for determining strength of

solution

Can be utilized for determining strength of solution

Cannot differentiate between different acidic or basic

solutions

Can differentiate between different acidic or basic

solutions

Examples: Litmus, methyl orange, phenolphthalein

Examples: pH paper, indicators

Colour Changes by Indicators

Contents Indicators

Basic Solution

Litmus

Methyl Orange

Phenolphthalein

Phenolphthalein (alkaline)

Red

Pink

Colourless

Colourless

Litmus (Alkaline) Red

Methyl Orange (alkaline)

Pink

Blue

Yellow

Colourless

Colourless

Blue

Yellow

Acidic SolutionAcid-Base Indicators

Utility of Indicators and pH Values

•Agriculture: The pH of soil is tested- for better growth of crops [citrus fruits need slightly alkaline soil, rice needs slightly acidic soil, and sugarcane needs neutral soil].•Dairies: A change in pH of milk [from 6.6] indicates that the milk has turned sour.

Contents Indicators

pH Values of Some Common Substances

•Dil. Hydrochloric Acid – 1.0•Lactic Acid – 6.6•Human Blood – 7.42•Sea Water – 8.5•Sodium Hydroxide – 13.0

Contents Indicators