9th grade Acid Base Intro notes 2017-18Here is a good web link (animation of water and self ionization (few words)

http://www.johnkyrk.com/H2O.html (taken from the packet called Acids and Bases Webquest 2014 internet packet.docx)

Follow along and WRITE IN YOUR NOTES THE STUFF HIGHLIGHTED IN BLUE

Simplest definition (Arrhenius) Acids: start with “H”, make H+ ions in solution with water

Examples: HCl, H2SO4, HF, H3PO4

Nomenclature: hydrochloric acid, sulfuric acid, hydrofluoric acid, phosphoric acid

Taste sour; have a pH less than 7 (pH < 7 )

Bases: end with “OH” make OH- ions in solution with waterExamples: LiOH, NaOH, KOH, Al(OH)3

Nomenclature: lithium hydroxide, sodium hydroxide, potassium hydroxide, aluminum hydroxide

Taste bitter, feel slippery (dissolve fats); have a pH greater than 7 (pH > 7 )

Ammonia (NH3) is a type of base called a Lowry/Bronsted base: (get used to drawing “conjugate pairs” which means identifying the one that is more acidic)

remember the ammonium polyatomic ion NH4+

NH3 + H2O NH4+ + OH-

There are 3 standard definitions of an ACID: Arrhenius: start with “H” and produce H+ ions in waterLowry-Bronsted: are a proton (aka Hydrogen cation) donorLewis: electron pair acceptor (used in biology when drawing Lewis dot structures)

There are 3 standard definitions of a Base: Arrhenius: end with “OH” and produce OH- (hydroxide) ions in waterLowry-Bronsted: are a proton acceptorsLewis: electron pair donor (used in biology when drawing Lewis dot structures)

How to determine if a solution is acidic or basic (alkali)pH is a special scale use to measure the Hydrogen cation (H+) concentration.

The concentration of H+ is so critical in the rate of chemical reactions (and the equilibrium of the human body) that we have a special scale for measuring tiny concentrations of the H+ ion called the pH scale.

pH means power of the hydrogen ion concentration

Water self ionizes (a little bit) to form: hydrogen ions and hydroxide ions, there are so many other water molecules around that the hydrogen ions really become hydronium ions

We Define equilibrium reaction that takes place in water as (more on pH later):

HOH(l) H+(aq) + OH-

(aq) but the equilibrium constant is small keq= 1 x 10-14

Really it’s 2H2O(l) H3O+(aq) + OH-

(aq)

(But I like to use H+ rather than a hydronium ion (H3O+))

Definitions:Hydrogen ion: (H+) a proton, a hydrogen atom that has lost its electron and is

really, really small (sub atomic)Hydroxide ion: (OH-) the part left over when a water molecule loses a

hydrogen ion, an oxygen atom with a hydrogen plus an extra electron.

Hydronium ion: (H3O+) a water molecule with an extra hydrogen ion attached.

Acids and bases react (neutralize to form a salt and water (in a double replacement reaction)

Try a few on the practice page: think of the ions present in the compounds and how they would exchange to form the new compounds(practice mono, di and tri protic acid identification as well)

End of day one notes:

Mathematically pH is a function defined as: pH = - log [H+] (pH is the negative of the log of the hydrogen ion concentration)

Exponent Review: Logarithm (log) Review:1x10-1 = .1 -log(.1) = 1

1x10-7 = .0000001 -log(0.0000001) = 7

1x10-14 = .00000000000001 -log(0.00000000000001) = 14

(Practice pH, pOH and H+ concentration on worksheet)

Acids and Bases react together and NEUTRALIZE to produce salt and water; earlier we called this a double replacement but when the reactants are and acid and a base we call it NEUTRALATION

Acid + Base salt + water (not just table salt, any salt)

Let’s try a few neutralizations (good review of balancing and predicting products as well) reactions; fill in what is missing.

Look at practice packet problems use periodic table to determine if cation or anion and of what charge

2nd day of notes: 4/19/17 before students are given the Take-home pH lab:

Have students draw the pH “triangle mnemonic”: bottom of triangle is the BASE and can have the BIG number (14); the top only has room for the “1” (a small number, and the apex of a triangle looks like a letter “A”), the number 7 goes in the middle (and in some European countries they put a slash in th e middle of a seven)

Acids: Dissolve metals, (producing H2 gas)react with carbonates to produce bubbles, low (1-7) pH,Must have hydrogen (often have oxygen as well), practice naming acidsturns Litmus paper RED, taste SOUR

When they ionize they produce H+ ions which combine with water to make the H3O+ (hydronium ion)

Bases: High pH (7-14), good for cleaning (like ammonia), turn litmus paper BLUE,taste bitterfeel slippery

Bases ionize to produce OH- (hydroxide ions)

Indicators: are a class of chemicals that undergo a visible color change in chemical environments that have a greater abundance of H+ or OH- ions.

Some important indicators:

Litmus paper : blue to red its acid; red to blue its basic

Bromthymol Blue: Blue in basic conditions yellow in acids

Phenolphthalein violet in basic conditions clear in neutral or acid

Anthocyanin: Cabbage juice indicator is _____blue/lavender__ in water (neutral)(aka Cabbage Juice Cabbage juice indicator is ____reddish pink________ in acidsIndicator) Cabbage juice indicator is _____green__________ in bases

Universal indicator (a mixture of four separate indicators that include, bromthymol blue, phenolphthalein, and methyl redROY G BIV (Know the colors in order. Do you remember which is the longest wavelength and therefore the lowest energy?)ROY G BIV The colors of visible light (in a rainbow)lowest energy or longest wavelength() to highest energy or shortest wavelength()

Some acids are poly-protic (means they can give up more than one hydrogen ion)HNO3 is monoproticH2SO4 is diproticH3PO4 is triprotic

It is similar for bases: NaOH is considered a “regular “ base (mono - hydroxyl)Mg(OH)2 could be considered twice as effective at neutralizing (or di-hydroxyl)

This terminology is not used as often and regular chemists instead use dimensional analysis with balanced chemical equations (called Stoichiometry) to solve these more complex problems,

Add these notes now:

Acids are formed from reaction of non-metal oxides and water

Ex: SO2 + H2O H2SO4 (not balanced)

Or CO2 + H2O H2CO3 (demo with BTB)

Bases are formed from metal oxides and water

Ex: CaO + H2O Ca(OH)2

Or MgO + H2O Mg(OH)2 (demo; with universal indicator)

Show demos of the color change of the indicators and tell trhem they should “read” their pH test paper (Hydrion (1-14)) right after testing a sample.End of 2nd day of notes

Strong acids completely ionize (change from molecules to ions)Would their Ka be greater than or less than 1?

Strong Bases completely dissociate (dissolve from their formula unit to their ions)Would their Kb be greater than or less than 1?

Weak Acids and Bases will try to remain together and will covert from their equilibrium positions as stress is placed upon them (water is just as weak an acid as it is a weak base)

Acids are formed from reaction of non-metal oxides and water

Ex: SO2 + H2O H2SO4 (not balanced)Or CO2 + H2O H2CO3 (demo with BTB)

Bases are formed from metal oxides and water

Ex: CaO + H2O Ca(OH)2

Or MgO + H2O Mg(OH)2 (demo; with universal indicator)

Neutralization occurs when the same number of Moles of acid reacts with an equivalent number of moles of base to stoichiometerically form a salt and water.

The equation to remember is: mLacid Macid = mLbase Mbase (volume times concentration = volume times concentration)Volume measured in milliliters and concentration measured in Molality (moles per liter)

A salt may hydrolyze (react with water) to form an acidic or alkali solution, depending upon its “parent” acid and base.

A parent acid and a parent base neutralize to for a salt that may be “acidic” like it’s parent acid ; basic (or alkali) like it’s parent base or neutral, equally acidic and alkali (more common)

Memorize these strong acids: HCl, HBr, HI,H2SO4, HNO3, HClO3(Chloric acid)HClO4(Perchloric acid)

and HC2H3O2 or CH3COOH as acetic (or ethanoic acid aka vinegar) a very common weak acid

Memorize these strong bases: LiOH, NaOH, KOH, RbOH, CsOH, FrOH, Ca(OH)2, Sr(OH)2, Ba(OH)2, Ra(OH)2 the alkali metals and the soluble alkaline earth metals.

And the base NH3 (ammonia) an important weaker base helps you understand Lowry-Bronsted conjugate pairs.

NH3 + H2O NH4+ and OH-

(NH3 and OH- are the bases; H2O and NH4+ are the acids)

Recap of titration calculations:

Complete neutralization occurs when there is just as much acid as there is baseFor mono protic acids and mono hydroxyl basesVolume of acid times the concentration of the acid will equal the volume of the base times the concentration of the baseOr more simply: mLacid Macid = mLbase Mbase (milliliters of acid times the molarity of the acid equals the milliliters of base times the Molarity of the base)

How many ml of .25 M HCl would be needed to neutralize 30.0 ml of .15 M NaOH?

9th grade Packet of Acid Base notes and practice work 2017 Given 4/11/17 1st page punched on 4/14 both pages turned in 4/17/17 (Monday)Here is a web link to an animation of water as it self ionization (few words) name:_________________http://www.johnkyrk.com/H2O.html Complete and balance these reactionsExamples of acid/base reactions:Acids and Bases neutralize to produce a “salt” and water (HOH or H2O)

1) H3P + 3 LiOH 3 HOH + ___ _________ neutralization (H3P is a tri protic acid?)

2) __ H2SO4 + __ Ni(OH)2 ________ + ________ neutralization (H2SO4 is a di protic acid?)

3) __ HI + __ CsOH __ HOH + _______ neutralization(HI is a mono protic acid?)

Acids and active metals produce a metal salt and hydrogen gas (H2)

4) __ Fe + __ HBr ___ H2 + ___ FeBr3 formation of Iron(III) Bromide

5) __ Cu + __ HCl __ ______ + ___ CuCl2 formation of copper(II) chloride

6) __ H3P + __ K 3 H2 + ____ ________ (mono, di or tri protic acid?)

7) _3_ H2SO4 + 2 Al ___ ______ + ___ Al2(SO4)3 (mono, di or tri protic acid?)

8) __ HI + __ LiOH __ LiI + _______

Acids and carbonates usually form: carbon dioxide, a salt and water:9) _2_ H3P + _3_ MgCO3 ___ CO2 + _1_ Mg3P2 + _3_ H2O

10) __ H2SO4 + __ Na2CO3 __ ______ + __ Na2S04 + __ H2O

11) __ HC2H3O2 + __ NaHCO3 __ HOH + ___ ______ + ___ _______

The activity series of metals Chemical Equations

Name: _________________________________ period: ____ Some metals resist being part of a compound and don’t react as much;

Look at the activity series for metals at the right: would Gold (Au) be at the top or bottom of this list

Note: Top of list is more active (more likely to be in a compound)

Metals from Li to Na will replace H from acids and water; From Mg to Pb they will replace H from acids only

Remember: (s) means solid, (aq) means aqueous (dissolves in water)

Predict if any reaction will take place. Balance the equations for any reaction that will occur

1. 1 Mg(s) + 1 FeSO4 (aq) 1 Fe(s) + 1 MgSO4 (aq)

2. Mg(s) + NaCl (aq)

3. Fe(s) + Pb(NO3)2 (aq)

4. Cu(s) + Al2(SO4)3 (aq)

5. Ag(s) + ZnS (aq)

6. Zn(s) + H2O (l) (is zinc active enough to react with water?)

7. Ag(s) + H2SO4 (aq)

8. Fe(s) + HCl (aq)

9. Na(s) + H2O (l)

10. Pb(s) + H2O (l)

11. Li(s) + Mgl2 (aq)

12. Al(s) + HCl (aq)

Name Symbol

Lithium Li

Potassium K

Calcium Ca

Sodium Na

Magnesium Mg

Aluminum Al

Zinc Zn

Iron Fe

Lead Pb

(hydrogen) H

Copper Cu

Mercury Hg

Silver Ag

The activity series of metals Chemical Equations

ANSWERS

1. 1 Mg(s) + 1 FeSO4 (aq) 1 MgSO4(aq) + 1 Fe(s)

2. Mg(s) + NaCl (aq) No Reaction

3. 1 Fe(s) + 1 Pb(NO3)2 (aq) 1 Pb(s) + 1 Fe(NO3)2

4. Cu(s) + Al2(SO4)3 (aq) No Reaction

5. Ag(s) + ZnS (aq) No Reaction

6. Zn(s) + H2O (l) No Reaction

7. Ag(s) + H2SO4 (aq) No Reaction

8. 1 Fe(s) + 2 HCl (aq) 1 H2(g) + 1 FeCl2(aq)

9. 2 Na(s) + 2 H2O (l) 1 H2 (g) + 2 NaOH(aq)

10. Pb(s) + H2O (l) No Reaction

11. 2 Li(s) + 1 Mgl2 (aq) 2 LiI (aq) + 1 Mg(s)

12. 2 Al(s) + 6 HCl (aq) 3 H2(g) + 2 AlCl3 (aq)

pH, pOH and how they relate to the hydronium and hydroxide concentrationsH20 dissociates to a very small degree to form hydrogen ions (H+) and hydroxide ions (OH-). The hydrogen ions always combine with a water molecule to form the hydronium ion (H3O+) but sometimes it is just easier to write H+

Water only ionizes to a very small degree (about 1 in 10,000,000) so we developed a logarithmic scale to measure this small concentration.HOH(l) H+

(aq) + OH-(aq) really 2H2O(l) H3O+

(aq) + OH-(aq);

[H+] =[OH-] = 1 x 10-7 moles per liter Remember le Chatelier Principal: if you increase the OH- concentration the H+ concentration decrease as more water is formed.Some just remember the dissociation constant for water:

Kw = 1 x 10-14 or Kw =[H+] [OH-] = 10-14

The concentrations of these ions is very important in many reactions so scientists (biologists) often keep track of these very small concentration using a logarithmic scale known as the pH scale.By definition:

pH = -log [H+] or (pH is equal to the negative log of the hydrogen ion concentration (In moles per liter))

pOH = -log [OH-] or (pOH is equal to the negative log of the hydroxide ion concentration (In moles per liter))Easy math trick: In water bases system: pOH + pH = 14 The system is easy to use: as the pH increases, the pOH decreasesComplete the chart:

[H+] pH [OH-] pOH Acidic, basic or neutral

1 x 10-7 7 1 x 10-7 7 neutral2 1 x 10-12 acidic6 8

1 x10-2

1 x10-2

110

1 x10-9

1 x10-13

1 x10-11

1 x10-5

1 x10-5

61 x10-4

pH practice1. Write the ionization constant equation for the dissociation of water.

2. What does pH mean?

3. Write out the formulas to change [H+] to pH and pH to [H+]

Substance [H+] (in mol/L) pH ___ Acid or Base ________Rank (#1 most acidic #11 most basic) Milk of Magnesia 3.16 x 10-11

Stomach acid 2.00 x 10-2

Sea Water 3.98 x 10-9

Blood 3.98 x 10-8

Coke classic 2.51 x 10-3

Pepsi 3.16 x 10-3

Diet Coke 3.89 x 10-4

Gatorade 1.12 x 10-3

Skin 1.00 x 10-5

Zest soap 1.26 x 10-10

Ivory soap 3.16 x 10-10

Just the easy stuff:Substance pH Acid or Base Rank

#1 most acidic #8 most basic

Grapefruit 3.15

Palmolive soap 9.75

Tomatoes 4.55

Soda crackers 8.20

Chocolate cake 7.4

Frozen strawberries 2.45

Camembert cheese 7.44

Cheddar cheese 5.90

Lowry-Bronsted Acids and BasesAn Acid is a proton(hydrogen ion) donor (if you want to donate you have to have one)A Base is a proton acceptor

A substance that can act as both a proton donor and a proton acceptor is said to be amphiprotic or amphoteric.For the following equilibriums identify(connect) the conjugate pairs and label each substance as a(n) Lowry-Bronsted acid or base. When completed see if you can identify (circle) any substances that acted as both acid and base (were amphoteric) in different ractions.

1) H2S + H2O H3O+1 + HS-1

2) HCl + H2O H3O+1 + Cl-1

3) HS-1 + H2O H3O+1 + S-2

4) HNO3 + NH3 NH4+ + NO3

-1

5) HNO3 + OH-1 NO3-1 + HOH

6) H2S + H2O HS-1 + H3O+1

7) H2SO4 + CO3-2 HCO3

-1 + HSO4-1

8) C2H3O2-1 + H2S HC2H3O2 + HS-1

9) HC2 H3O2 + HPO4-2 C2H3O2

-1 + H2PO4-1

10) C2H3 O2-1 + NH4

+1 HC2H3O2 + NH3

Neutralization occurs when the same number of Moles of acid reacts with an equivalent number of moles of base to stoichiometerically form a salt and water.

The equation to remember is: mLacid Macid = mLbase Mbase (volume times concentration = volume times concentration)Volume measured in milliliters and concentration measured in Molality (moles per liter)

A salt may hydrolyze (react with water) to form an acidic or alkali solution, depending upon its “parent” acid and base.A parent acid and a parent base neutralize to for a salt that may be “acidic” like it’s parent acid ; basic (or alkali) like it’s parent base or neutral, equally acidic and alkali (more common)

Memorize these strong acids: HCl, HBr, HI,H2SO4, HNO3, HClO3(Chloric acid)HClO4(Perchloric acid)

Should also know: HC2H3O2 or CH3COOH as acetic (or ethanoic acid aka vinegar) a very common weak acid

Memorize these strong bases: LiOH, NaOH, KOH, RbOH, CsOH, FrOH, Ca(OH)2, Sr(OH)2, Ba(OH)2, Ra(OH)2 (the alkali metals and the soluble alkaline earth metals).

Recap of titration calculations:

Complete neutralization occurs when there is just as much acid as there is baseFor mono protic acids and mono hydroxyl basesVolume of acid times the concentration of the acid will equal the volume of the base times the concentration of the baseOr more simply: mLacid Macid = mLbase Mbase (milliliters of acid times the molarity of the acid equals the milliliters of base times the Molarity of the base)

1) How many ml of .25 M HCl would be needed to neutralize 30.0 ml of .15 M NaOH?

2) How many ml of .15 M HCl would be needed to neutralize 45.0 ml of .1 M NaOH?

3) If 45.2 mL of 0.125 M NaOH is need to neutralize 10 mL of a monoprotic acid solution what is the molarity of this acid solution?

4) If 325 mL of 0.10 M NaOH is used to neutralize a 25 mL of an acidic solution what is the molarity of hydrogen ions in this acid solution?

Important reactions involving acids and basesAn acid and base will NEUTRALIZE to for a salt and waterAn Acid and a carbonate will DECOMPOSE to release carbon di-oxide forming a salt and water.And acid and a metal will react (corrode) to form hydrogen gas and a metallic salt.Predict the products and balance as necessary.

12) HCl + Na OH H2O + NaCl neutralization

13) H2S + 2 NaOH 2 H2O + ___________ neutralization

14) H3P + 3 KOH 3 H2O + ____________ neutralization

15)__ H2SO4 + __ AL(OH)3 ________ + ________ neutralization

16)__ HI + __ LiOH __ HOH + _______ neutralization

17) __ Fe + __ HCl ________ + _________ formation of Iron(III) chloride

18) __ Cu + __ H2SO4 ________ + _________ formation of copper(II) sulfate

19) __ Mg + __ H2CO3 ________ + _______ form magnesium carbonate

20) __ Cu + __ H3PO4 ________ + _________ forms of copper(II) phosphate

21) __ NaHCO3 + __ HCl ________ + _______+ H2O formation of NaCl

22)__ Na3PO4 + __ HCl ___ _____ + __ _____ again forms sodium chloride

23) __ Li2CO3 + __ H2S ________ + _______+ H2O forms lithium sulfide

Predict the acids and bases that had to react to form the following salts:24) _______ + _______ __ K2S + __ H2O neutralization

25) ________ + ________ __ H2O + __ MgBr2 neutralization

26) ________ + ________ __ H2O + __ FeCO3 neutralization