- Properties- Arrhenius Acids and Bases- Naming acids and bases

Mr. Shields Regents Chemistry U15 L01

Bases

Acids

PropertiesPropertiesWe’ve all encountered acidsand bases in our Daily lives.

For example all of thesecommon items are examplesOf acids or bases

Other examples are:Acid Rain TeaCoke Car batteriesAnts Antacids

What kind of properties doThese substances exhibit?

PropertiesPropertiesAcidsAcids BasesBases

Taste SourTaste SourFeel like waterFeel like waterReact w/ bases to form React w/ bases to form water & salt (neutralization) water & salt (neutralization) React with metals to React with metals to produce Hproduce H22 & salt (Table J) & salt (Table J) Good electrolytes Good electrolytes

i.e ionizes & conducts i.e ionizes & conducts electricity in solutionelectricity in solution

AciAcidds turn litmus res turn litmus redd What color is the paper?What color is the paper?

Phenolphthalein turns Phenolphthalein turns colorlesscolorless

Taste BitterTaste BitterFeel slipperyFeel slipperyReact with acids to form React with acids to form water & salt (neutralization)water & salt (neutralization)Won’t react with metalsWon’t react with metals

Good electrolytes Good electrolytes BBases turn litmus ases turn litmus bbluelue

What color is the paper?What color is the paper?

Phenolphthalein turns Phenolphthalein turns pinkpink

Reaction with MetalsReaction with Metals

OK. So …What metals will react with acids?OK. So …What metals will react with acids?

See Table J to figure this outSee Table J to figure this out

All the metals above All the metals above HH22 will react with acids. will react with acids.

Cu, Ag, and AuCu, Ag, and Au do notdo not react with acids. react with acids.

Mg is above H2 in Table J so this reaction proceeds as indicated. What kind of rxn is this?

Single replacement (why)

Redox (why?)

Example: 2HCl + Mg MgCl2 + H2

2H+ +2e- H20 (red.)

Mg0 Mg+2 +2e- (ox.)

Mg replaces HWhat kind of rxn is this

(a salt)

Problem: Will the following reaction proceed as indicated?

6HCl + 2Au 3H2 + 2AuCl3

No. Gold is below Hydrogen in Table J

Problem: Will the following reaction proceed as indicated?

6HCl + 2Co 3H2 + 2CoCl3

Yes. Cobalt is above Hydrogen in Table J

Neutralization ReactionsNeutralization Reactions

Acid + Base Acid + Base Salt + Water Salt + Water

A Double Replacement ReactionA Double Replacement Reaction

HCl + NaOH HCl + NaOH NaCl + HOH NaCl + HOH

This is Not Redox (How do I know?)This is Not Redox (How do I know?)

What kind of reaction is this?What kind of reaction is this?

Acid + Base Salt + Water

HCl(aq) + NaOH(aq) NaCl(aq) + H2O(l)

What is the Ionic Equation for the above rxn?

HH++((aqaq) +Cl) +Cl--((aqaq) +Na) +Na++((aqaq) +OH) +OH--((aqaq) ) H H22O(l) +NaO(l) +Na+ + ((aqaq)) ++ ClCl--

((aqaq))

This works because H+ + OH- H2O (a Molecule)(one of the ways double replacement goes to completion)

Which ions are the spectator Ions?

NaNa++ and Cl and Cl-- are spectator ions are spectator ions

NeutralizationNeutralization

Arrhenius TheoryArrhenius Theory

An early attempt (1884) to explain acids andAn early attempt (1884) to explain acids andbases is known as the bases is known as the Arrhenius TheoryArrhenius Theory..

-This was the first successful definition ofThis was the first successful definition of what an acid and base iswhat an acid and base is

-It was based on It was based on what ionwhat ion is released is released when the Compound is dissolved in waterwhen the Compound is dissolved in water

Arrhenius TheoryArrhenius Theory

- According to Arrhenius, Acids areAccording to Arrhenius, Acids are compounds that contain hydrogen and compounds that contain hydrogen and ionizes in water to yield hydrogen ions (H+)ionizes in water to yield hydrogen ions (H+)

Examples:Examples:

HCl + H2O H+ (aq) + Cl-(aq)H2SO4 + H2O 2H+ (aq) + SO4

2- (aq)

Arrhenius TheoryArrhenius Theory

Take out your Reference Tables. Look at Table K

Table K list the name and formulas of somecommon acids.

ALL of these Acids areArrhenius acids.

They all produceH+ ions in sol’n

Naming Binary AcidsNaming Binary Acids

A binary acid is an acid with only 2 elements. A binary acid is an acid with only 2 elements. They are named as follows:They are named as follows:

Hydro + Stem of nonmetal ion + icHydro + Stem of nonmetal ion + ic (ex. Chlor(ex. Chlorideide Chlor) Chlor)

HF = ? HF = ?

HI = ?HI = ?

HCl = ?HCl = ?

Hydrofluoric acid

Hydroiodic acid

Hydrochloric acid

Naming Ternary AcidsNaming Ternary AcidsA Ternary acid is composed of 3 elements. The A Ternary acid is composed of 3 elements. The Name is derived from the Name is derived from the polyatomicpolyatomic anion (see anion (see Table E)Table E)

Replace –Replace –iteite with – with –ousous plus acid plus acid NONO22

-- is nitrite is nitrite HNOHNO22 is nitrous acid is nitrous acid

Replace –Replace –ateate with – with –icic plus acid plus acid NONO33- is nitrate - is nitrate

HNOHNO33 is nitric acid is nitric acid

Ternary AcidsTernary Acids

For polyatomics with S and P, the stem For polyatomics with S and P, the stem becomes long again.becomes long again.

HH33POPO44 = = phosphorphosphoric acid, not phosphic acidic acid, not phosphic acid

HH22SOSO44 = = sulfursulfuric acid, not sulfic acidic acid, not sulfic acid

HH22SOSO33 = = sulfursulfurous acid, not sulfous acidous acid, not sulfous acid

Kinds of AcidsKinds of Acids

Acids can produce one or more protons (H+)Acids can produce one or more protons (H+)When dissolved in water.When dissolved in water.

-Acids that release Acids that release one H+one H+ are called are called MONOPROTICMONOPROTIC

example: HCL + Hexample: HCL + H220 0 HH++ + Cl + Cl--

- Acids that release Acids that release two H+two H+ are called are called DIPROTICDIPROTIC

example: Hexample: H22SOSO44 + H + H220 0 2H+2H+ + SO + SO44-2-2

Kinds of AcidsKinds of Acids

- Acids that release Acids that release three H+three H+ are called are called TRIPROTICTRIPROTIC

example: Hexample: H33POPO44 + H + H220 0 3H+ + PO 3H+ + PO44-3-3

Notice Table K also lists CHNotice Table K also lists CH33COOH (COOH (acetic acidacetic acid))- this is an “organic” acid- this is an “organic” acid- It has only one ionizable H+ (- It has only one ionizable H+ (i.e monoprotici.e monoprotic))

CHCH33COOH + HCOOH + H220 0 CH CH33COOCOO-- + H + H++

The ion CHThe ion CH33COO- is known as the COO- is known as the AcetateAcetate IonIon

Types of AcidsTypes of AcidsWhat are the What are the namesnames of the following acids, what of the following acids, what KindKind of acids are they and of acids are they and how many protonshow many protons are are released when the acid hydolyszed in water?:released when the acid hydolyszed in water?:

HNOHNO33

HH33POPO4 4

HNOHNO22

HH22SOSO44

HIHI HH22COCO33

HH22SOSO33

CHCH33COOHCOOH

Arrhenius BaseArrhenius Base

According to Arrhenius an acid is a According to Arrhenius an acid is a substance that contains hydrogen and substance that contains hydrogen and produces produces HH++ in aqueous solutions. in aqueous solutions.

So how did Arrhenius define a base? So how did Arrhenius define a base?

A substance that contains hydroxide and A substance that contains hydroxide and produces produces OHOH-- as the only negative ion in as the only negative ion in aqueous solution.aqueous solution.

Arrhenius BasesArrhenius Bases

According to Arrhenius a base is a compoundAccording to Arrhenius a base is a compoundThat ionizes in water to yield HYDROXIDE (OHThat ionizes in water to yield HYDROXIDE (OH--))

Example: Example: NaOH + HNaOH + H220 0 Na Na++ + OH + OH--

Table L list some of the Table L list some of the More common bases.More common bases.

All of these bases are All of these bases are Arrhenius bases Arrhenius bases exceptexceptNHNH33. We’ll discuss NH. We’ll discuss NH33

Later.Later.

Naming BasesNaming Bases

Naming hydroxides Naming hydroxides metal name + hydroxide metal name + hydroxide

MonohydroxyMonohydroxy

NaOH = ?NaOH = ?

DihydroxyDihydroxy

Ca(OH)Ca(OH)22 = ? = ?

Mg(OH)Mg(OH)22 = ? = ?

TrihydroxyTrihydroxy

Fe(OH)Fe(OH)33 = ? = ? Iron Iron (III)(III) Hydroxide! Hydroxide!

Problem:Problem:

Correctly identify which pair is an Arrhenius acid Correctly identify which pair is an Arrhenius acid and Arrhenius base:and Arrhenius base:

HCl and NaClHCl and NaClHH33POPO44 and Ca(OH) and Ca(OH)22

HH22COCO33 and CO and CO22

HNOHNO33 and NH and NH33

HH33POPO44 and Ca(OH) and Ca(OH)2 2 are the correct choice are the correct choice because phosphoric acid donates Hbecause phosphoric acid donates H++ and and Ca(OH)Ca(OH)22 because it donates OH because it donates OH--

Base preparationBase preparation

Group 1 metals Group 1 metals react vigorouslyreact vigorously with water to with water toproduce hydroxidesproduce hydroxides

Remember the reactions we did in class?Remember the reactions we did in class?

2Li + 2H2Li + 2H220 0 2LiOH + H 2LiOH + H22 Fast ReactionsFast Reactions

2K + 2H2K + 2H220 0 2KOH + H 2KOH + H22

2Na + 2H2Na + 2H220 0 2NaOH + H 2NaOH + H22Group 1 hydroxides are VERY SOLUABLE in water

Base preparationBase preparation

Group 2 metals Group 2 metals react less vigorouslyreact less vigorously than than Group 1 metals with water.Group 1 metals with water.

Ca + 2HCa + 2H220 0 Ca(OH) Ca(OH)22 + H + H22

Mg + 2HMg + 2H220 0 Mg(OH) Mg(OH)22 + H + H22

Group 2 hydroxides are only Group 2 hydroxides are only very slightly solublevery slightly soluble in water. in water.

Ca(OH)2 = 0.165g/100mlCa(OH)2 = 0.165g/100mlMg(OH)2 = 0.0009g/100ml Mg(OH)2 = 0.0009g/100ml Suspended in water this is Suspended in water this is

known as Milk of Magnesiaknown as Milk of Magnesia

Acid/Basic OxidesAcid/Basic OxidesMetal and non-metal oxides when dissolved in water formacids and bases.

Non-metal oxidesproduce acids

CO2 + H20 H2CO3

Metal oxides produce bases

K20 + H20 2KOH