UnitE

Acids and =Bases

°0

Perio TEST" ÿ• i i

! : i

Unit 13 - Acids and Bases - Calendar

APRIL

11Notes: pH scale:

HW: Pg. 9

Alien Juice Bar

Computer Lab

DUE!

Review

18PHET Computer Lab

12Go over Gas Law,

Bonding, and

Solutions Tests

HW: Study for

Cumulative Exam

19

7th

SOLUTIONSTEST

if>- 4

. Cumulative "ÿ and pOH:alÿulations -TEST ÿ/ath Practice

v: eg 12

iN/2-'21

Titrations - Pre Lab Titrations

Bth

/ideo: Acids & Bases

Jotes #1&cids and Bases

Characteristics and

Arrhenius and Bronsted

Lowry definitions

HW: Pg. 6

15uiz?!?!?!

grossword puzzle

ag 13-14

14alf dayEnd of 5th six weeks

22l"itrations

Neutralization andTitration Notes

HW: Pg 17

HW: Study Guide

g 18-21

RW: Study Guide

Pg 18-21

25 26STUDY GUIDE o2ÿ.'

Bases )TIEST ÿ )

Notes #1: Introduction to Acids and Bases

Acid:-3'

Properties of Acids:

o ÿ>K >uÿf -*" .s ÿ --Vw (leman juice)

Commÿ,n Household AÿIdÿ & Elaÿs

o

o

0

0

0

0

0

o

Both strong and weak

Will cause indicators to change colors

• Acid + Metal -)

Double replacement reaction

• Acid + Base ÿ ÿiu'ÿ4"ÿ÷s,ÿ"ÿ + a

a u H

Examples: HCI, soda, coffee

Naming Rules: "/ ÿ;ÿ ..... ÿ "'

EX:

:-ite "

-ate ;

Examples of Naming Binary Acids

• HF ÿ'ÿ'W ÿ ÿz =Ibÿt," L. (4(. {.ÿ.

• HBr t,{,,ÿ;' ÿ;I (0 ,ÿ..-

EX: Examples of Naming Ternary Acids

• HzSO4 Sulfate is the poly, so

• HzCOÿ Carbonate is the poly, so

• HzNOÿ Nitrite is the poly, so

Actdÿ ÿaÿeÿ

• I'NO hydro-beginning:. ÿ:I " '"'i:: ÿ " .. -OUS " 'i

NO hydro- beginning -ici

........ - ' - ;: ........ . --z""ÿ' hydro, beginning:: 7:7 ii : 71i!i: ]:; i",, -ic, " .... :i i7'ÿ ; i ii

uU-'>uÿ.- +.%

BQSe:I

Properties of Bases:

o

o

0

o

0

0

o

(soap)

Both strong and weak'.i," i !,ÿJi/>.

Will cause an indicator to ,ÿ : ...... ,.ÿJ

)

Examples: NaOH, soap, antacids, drano, bleach

colors

Naming Bases

• The easiest are the bases, since most of these are

compounds you already know how to name.

.hydroxides,

Metal hydroxides are named in the same way any other ionic compound is

named. First give the name of the 7sq "' "

the name of the anion, which, in the case of bases, is"

ion. Follow this with#,

• KOH- I/.-v,::ÿ:?lÿ'',,

Mg(OH)2-

Other definitions of Acids and Bases

Arrhenius Acids and Bases:

o Acid:

Base:

BrCnsted - Lowry Acids and Bases

o They felt the Arrhenius definition was too limiting.

o Acids: ÿ ÿ. ÿ." ÿ'iÿ ÿ'ÿI t

t/wi, " t.tÿ+'ÿ}"

BrCnsted - Lowry Acids and Bases cont.

o Bases: ÿ7i!( Y'19,:'ÿ4"ÿ n"

• Ex: NHs + HzO 4--) NH4++ OH

I ....,. ...... .ÿ Iÿ L if>

!J7:: i.ÿ ,.,..*>} I--,:J '. c

4

Amphoteric: ..... ) ÿs., - i ÿ, f ÿ;ÿ'

o Ex: HCI, NaOH

Weak Acids/Bases: '!'i'ÿ(Jÿ. "ÿ 0 .'ÿC.;!.'ÿJÿ', . .'

o Ex: NHs, Acetic Acid (vinegar)) I

o Tooth decay is caused by the weak acid - lactic acid: C3HÿOs

,,) I...O ......

o"

,+

Cÿ

• Will produce a light bulb

• Examples of Acids and Baÿes that are Strong Electrolytes:

breaks apart into its ions

conductors of

Strong Electrolytes

• Are c,l {.:i,.l.!/

electriciW

F

jÿ

Weak Electrolytes

• Are ÿ.i ,.' :;

• ,electricity

• Will producea

breaks apart into its ions

conductors of

I'Wÿ light bulb

Examples of Acids and Bases that are Weak Electrolytes:

i

/

h

HOMEWORK - DAY 1 NOTES

Identify the following properties as to Acid, Base or Salt.

1. acid + base -> water + ?

2!. Tastes sour

3. Turns litmu¢ red

4. Produces [H307 in solution

5. Neutral solution

6, Produces the [OH'] in solution

7. Neutralizÿs an acid

8. ? + metal --ÿ hydrogen ges

g. Feels slippery

t0. Usually has oFr in the formula

,.-ÿ..+ I}

-ILt<i;. [

Note that H30+ ions are "hydrated" hydrogen ions. H+ and H30÷ are interchangeable.

H÷ + H20 -- H30+

Which picture at right is the:

1. Strong electrolyte

2. Weak electrolyte__

A B

IDENTIFICATION - Identify the following examples as:A = acid B = base S = salt (neither acid not base)

Remember from the previous units, a salt is any ionic compound, excluding what we classify as a base.I_. AgOH !ÿ 7. Mg(OH)2Mgso B

,(ÿ 3. ZnC03

4. H2S04

Aÿ 5. NaOH6. HCIO

,i:i, 9. Pb(CIO)2<ÿ, 10. (NH4)2CO3

11. HC2H302

/:ÿ 12. HBr

pH SCALE Notes: pH and pOH/i p ÿR

SmallStomach Intestine Blood

I I I0 1 2 3 4 5 6 7 8 9 10 11 12I I I I I I I I I I I I I

13 14I I

Battery OrangeAcid Vinegar jutce Milk Sea Water Bleach

MEASURING pHScientists use a pH scale to measure the strength of an acid or base. The term pH stands for "potential forhydrogen". The amount of hydrogen in a substance determines its acidity or alkalinity. Alkaline is anotherterm for base. A number on the pH scale is used to describe the strength of acidity or alkalinitv, The mostcommonly used pH scale goes from 1 (very acidic) to 14 ( very basic). The number 7 on a pH scale meansneutral - neither acid nor base.

The concentration of hydrogen ions in a solution is described by its number on the pH scale.A pHtells you that the concentratlon of ,": ÿIr J' ,,?ÿ ,;>? A,">ÿ

. ;..,, ,-) .... j.

b'ÿ EX: pH 2• By ÿompÿarlson, a ÿ

on is

Self-ionization of water:v' ,..U;" "

ion

pH tÿlls you that the concentratlon of

oFV . EX: pill2

• uv ;q Ic,tÿ L-

• 1-120 + H20 -'ÿ OH" + H30+

• Also written as: 1-120 -'ÿ H+ + OH

• The H30* and H* represent hydrÿen ions in solution.

Neutral Solutions

• In pure water, the concentration of hydrogen ions is

hydroxide ions• 1xlO'7M orpHo$

o (Remember that M is the unit for Molarity)• [H÷I=[OH]

o (brackets represent concentration).

• The represents a U!ÿiJÿil

,9 x; .'4to the concentration of

Solutions

;.ÿ I/I Iÿ<i(7]-

2&

In a solution, if the [H+] the [OH-]

.... 1 7-7

.. f ,_.. ;s- - and vice

versa.

o Think back to our see-saw. As one "person" goes up the other "person" goes down.

Ion-product constant of water, Kw:

• Kw = [H+I x [OH'I = 1 x 10"14 M

Acidic Solution:

The [H+] is .: than [OH]. .ÿ" S ? ';J " 'ÿ' "Therefore, the [H+] is c-ÿ, X. ÿ,ÿ .{ÿ" { ÿ;'- I< V'ÿif

o , <ÿ/.4- "ÿ'<- .... ÿ

Basic Solution:

• The is [H+] ÿthan [OH].• Therefore, the [H+] is

A.k.a. ÿ')li}ÿsÿ ('I(ÿ-"• o'II

+ If*÷

÷

÷

÷

÷÷

Let's review:

AcidsComplete the chart below:

Bases

Type of

Acidic

Solution

Neutral

Basic or Alkaline

t

[H+]

.

Homework:Use the pH scale on page 7 to rank battery acid, vinegar, orange juice, milk, and bleach in

order of increasing acidity.

"j /

,

I.. Acid

3. Nÿtrl Q/

Complete each section:

A. To m= ÿdÿ and baÿeÿ tÿ cancd ca&vflÿ-r out aad m&ÿ sÿ/ÿ watt'.

:1 Bo A eÿmpound &ÿt adÿh H+ iÿns tÿ watt'.:i

C Eq=al numbÿ'*f H+ mt OH- iota;

4. Nÿ'tra[-m /(ÿ D. A eÿmpotmd tÿal ad& 0tl- iota ÿo¥;ÿtel".

t.pH

2. Saltÿgaÿx (/,

i Sÿong Add ÿSi

B. A eo=ÿ=d tsar ÿaaÿ a ÿw OH- ioÿ

C. The product of a ÿetÿtmlLÿmlion reÿcfionet-a, een ÿ acid ÿd a baÿ.

4.%Veÿ Baÿ D.wate=Ac°mP°mÿd tMt ÿ:l& afewH+ ÿoÿto

i AddRakt ÿ ....... Eÿ ÿ%entmlIutiÿncaw*ÿ rÿtÿ be acidi -- 5.We&Adÿ [) E..A compoÿmd thatad& alot of H-+ioÿ

%ieh ÿne hmÿ more I-g+ iÿm? ÿ;ÿ

"f ÿHÿ,ÿS NaOH iiO}I..... S-.ÿ--

.................... ÿ .................... ÿ.

Adts or Bases-? (bSmO

Has fewer OH-r iota: ÿ o£ I iv 7: 5 , : ,q

H o£7 ÿ 14:

Fÿs ÿRÿIÿ3c

Taste: ÿom<.

/Z-

Which one hsÿ more Oil- ioÿ? ÿ/ÿ

Wld& onÿ hÿs hÿ= H+ iota?

Each vocabdlary term is by an example and a nonexample.to the example of the vocabulary term.

a check mark (,/) next

1, Strong Acid

qA 0.1 M HBr solution produces OAOM of HaO* and O.IOM of Br°" A 0.1 M HF solution produces O.01M of H.ÿO÷, 0.01M of F', and

2. ,Stron9 Base'A"ba"si'0' 'compound that does not easily dissolve in water

1 I A basic compound that dissolves easily in water but does

3. Weak Acid

::' .................

lÿLithium hydroxide (LiOH), pH 8[ I Ammonia (NHa), p-12i

pH CALCULATIONS

JÿÿpH = -Iog[H+]

pH[H÷] [OH-]

[H÷]

Remember: The pH scale ranges from 0-14

0 0= "J ,-'' f f : .... ÿ ÿ,t :,

What is the pH of a neutral solution?

o Calculate usingthe Loqorithmicfunction on the calculator ÿÿ

( see photo to the right)

Sample Problems

As long as you have a x 10 to some power, the pH is the exponent. If the number before the

"xlO" is anything other than 1, you MUST use the formulas to find the pH.

, What is the pH of the following concentrations?

a. [H+]=lxlOlzM = iJ,, ÿ',<ÿ ÿ .......

,

b. [H*] = lx lO'e M=

c. [H+I=lxlO'SM: /ÿSf' (ÿtd

What is the pH of the following concentrations? Use pH = - Iog[H+]

a. [H+]=2xlO'zM=

{ 'ÿ {i ........

b° [H+] = 6 x 10-9 M =

} ts, ix%/

C. [H+] = 3 x 10"s M =

W/ { /M/ / 10

Other Formulas and Problems

• pH 14 = pH + pOH (see example 1 below)

• Using the Equilibrium constant labeled as

• Kwis ÿ ', i) -

-ÿ -, -ÿ .....ÿI-ÿ xi'ÿ:ÿJlÿ• Kw= i_L ri ÿ- 7

EX: What is the pH of a solution with a [OH] of 4.0 x 1011M?

Use Kw to find [H÷] then find pH using -log .function.

- ÿI ÿ ÿ x ÿ ÿi

3. What is the hydrogenH÷ or OH?

mn concentration of a solution with a pH of 11? Which has a greater concentration:

F S .........

4. A solution has a hydrogen ion concentration of 1.2xl0UM. Determine the pH of the solution. Is this solution

acidic, basic or neutral? {ÿi! ÿ! ...... iÿ) ,,ÿ iI ÿ. "'i

25°C when the H+ concentration is

S f fÿ W I ""

jfj.. .............. . '

.."i ÿ 7 >, ,- IV{J sÿ .9.'ÿ.'" ÿ

Homework Practice Problems on pHSolve the following problems. Be sure to show work for each problem.

1. Determine the pH of a solution that has a hydrogen ion concentration of 1.0x10-gM.

Is this solution acidic, basic, or neutral?

2. Lime juice has a hydrogen ion concentration of 1.3xi0-ÿM, while the [H÷] in lemon juice in 0.067M.

Calculate the pH for each juice.

f pHoflemon= ! ÿ

pH of lime =

Which is more

F hthe hydrogen ion concentration for a solution with a pH of 8?

1 rWhat is the pOH of the /---vf'Y-ÿ ,ÿ-__,

4. Knowing Kw = lxlO14, calculate the molarity of OH- in solutions at 25°C when the H÷concentration is:a. 5 x 101° M

b. 100 M Cÿtÿ, ÿ.ÿÿ

I®5. Determine the pH of a solution if the [OH-] = 4.93 x 10.8 . (Hint: solve for [H÷] using Kw, then pH)

12

REVIEW OF ACID/BASE PROPERTIES AND ELECTROLYTES

v

0O

L

1

IA

UI

j

Vÿv ©

J ,

I

t<..

VVLQÿ

v0ii

0_

1

I0Dd

Lrÿi

N

©

wL/

corrosive

brightacidic

amphoteric

hydrogen

strong

neutral

weak

acid(s)bitter

WORD BANKdimallhydroxide

base(s)sour

slipperyabove

hydronium

red

electrolyte

below

I (ÿ Chemistry

metals

blue

basic

13

Hints for the Crossword Puzzle

Across

4. able to act as an acid or base. ÿ PÿDÿ'ÿI ÿ,"

6. Bases have a ÿ/ÿJÿ" taste.

9. ÿ1/ solutions contain hydrogen and hydroxide ions.

10. Acids will react with ÿ/ÿ/ÿ iÿ to produce hydrogen gas.

14. Acids have a ÿ01ÿ taste.

17. An acid or a base can be called a(n) ÿlÿOÿ3ÿi ÿ]ÿ because either can

conduct an electric current.

18. For a weak electrolyte, the light bulb will be ÿ i

19. the name of the ion commonly found in bases ÿ/C1ÿ0 ÿ1ÿ20. A LÿJÿ electrolyte will partially dissociate.

Down

1. A ÿ6rVÿ electrolyte will completely dissociate.

2. harmful, destructive, caustic 0ÿ) ÿ(ÿ)ÿ Iÿÿ3. the type of solution that has a higher hydrogen ion concentration the hydroxide

ion concentration

4. Fruits and vinegar are examples of

5. Bleach, ammonia, and soap are all examples of

7. Bases feel ÿ/1ÿÿ

8. For a strong electrolyte, the light bulb will be11. For bases, the pH is 0ÿ ÿ0 ÿ,/ÿ

12. Bases turn litmus paper iÿ ÿÿ ÿ

13. For acids, the pH is ÿCÿ seven.

seven.

15. the color of pH paper in an acidic solution

16. the element commonly found in acids

14

Neutralization Notes

• Acid-Base reactions will produceneutralized.

• Salts are compounds consisting of a(n)'ÿUI Vÿ 10ÿ

(;ÿ'ILÿ 0 .ÿL" from a base.ra' Iÿ'1" ÿoÿ<J'ÿ i ,d and a

• Ingene I, reac ns" h'chanac" ÿaÿ_e

water is called Neutralization Reactions. ' "fit• Neutralization occurs when an Acid + Base <-->

'ÿP-'ÿ when completely

from an acid and a(n)

react in an aqueous solutbnÿo produce a salt and

o Salt: Anion from acicl and the cation from the base join together to form a salt.

Where do we see this process?

o Farmers controlling the ÿ

o Formation of ÿV'ÿ{ÿ

Practice:

of soil

A strong acid + a strong base = neutralsolution

o Examples:

• HCI + NaOH <l> H20 + NaCI

• HCI + KOH <-> H20 + KCI

Don't forget to balance them after you write them.

HCI + LiOI=F-ÿ ÷ Li ci

15

TitrationsTitration: "ÿ?-1 ÿ:ÿ)ÿf0Cÿ 0ÿ 01ÿ/,ÿIVÿ ÿ ÿUÿ, tÿ{vÿUIiÿ"

f you dont know the n entrat" n f ne solution, you can figure it out by performing a

neutralization reaction, or titration, with a ÿ"£4 ÿ £ÿ ÿ ÿ'ÿ,ÿ Sÿ) L)Iÿ]Oÿ"ÿ

o A standard solution is one of ÿVÿ0ÿJ PI COÿfÿ Cÿ/ÿ'JÿKiJhbl/-ÿJ

• Performing Titrations

o Steps in a neutralization reaction:

• A measured volume of an ÿ (Ji (ÿ solution of L) Vÿ ÿ'LJÿ6 [A//ÿ

concentration is added to a flask.

Several dropsof IVÿiÿÿ ' (ÿihÿl/lÿÿ 'ÿ ÿ ÿ[ Gÿ-are acldea to the solution %,

Measured volumes ofa ÿ0ÿ@J with a ÿiAJ!ÿrÿconcentraÿlon aÿeÿ xÿed inÿ/o thee aÿdÿÿrÿ)until it barely changes color.

End Point.: ÿV'ÿÿj ÿ01Vÿ ÿ."ÿ ÿJÿhl(ÿ-ÿ/ÿ-/ IIY}AIÿA'ÿÿ (ÿ{ÿVÿ.

• Once you havle reached the end point, you can perform calculations to find the unknowLÿn CD/ÿ'ÿ

solution. (ÿ ÿlÿOÿ If "ÿ ?1ÿ P)

3. Example: A 25 mL solution of HzSO4is completely neutralized by 18 mL of 1.0 M NaOH. What is the

concentration of H2SO4 solution?

a. Step 1: Balance Equation

• 1 HzSO4+ ÿNaOH-> I NazSO4+ ÿHzO

b. Step 2: Use this formula to solve for unknown concentration.

• na = number of ÿt0ÿ of your

• nb= number of I/1/ÿ0!ÿ of your

-: M Vb

l16

.eu,. iza, on.ea.,on..ana,obe.ske, ke,hs

1. How many moles of HCI are needed to neutralize 6 tools of KOH?

a. ist ask, what is the mol ratio and then set it up as a proportion{ iFfÿ£ÿ-I/x ÿ',ÿ,/ ÿÿ.

I m01 .tÿcl = ! ÿ01%0m0! FrCl = b m01 .trio

, HzS04 + 2NaOH (----) NazS04 + 2HzO1 I

a. One mole of sulfuric acid is needed to neutralize -ÿJ 0 moles of NaOH.

b. How many moles of NaOH are needed to neutralize 4 moles of H2S04?

Neutralization and Titrÿt-io"#,Heÿ'eÿ6rÿ%/k..,A-ÿ

1, What is the purpose of a titration?

2. Why qo you neea an ingicaÿor inZ a t'itration..

3. What ÿs the enapoint? ..... ÿ ÿ C,I , Iÿ ÿCI) ,

4. Why is it i, rpportantÿ notto ÿovershoot" tbe.,tjtration? Refer to your anÿ'Twer to #1.

dÿtll n0ÿ ÿt ,rvÿ Owfÿ,rPr5. Calculate the molarityÿl: an acetic acid solution if :34.57 rnÿ_ of this solution are needed to neutralize 25.19 mL

of 0.1025 M of sodium hydroxide. Balance the equation as needed!!lÿ

_.ÿ_.HC2H,02 (aq) + ÿ NaOH (aq) "-) } Na C2H,O2iaq) +__'] H20 111

o. ÿo ÿ, o, o.oo ,,,, ÿo,ÿ,u,,, ,ÿ,,,ÿrox,de neut,a,¢¢'?ÿ-ÿ, oÿ sÿ,u,ÿ ad,ÿ. ,:,etÿÿtrÿÿ.'ÿ

BALANCETHE EQUATION FIRST! I___H,SO4laq) + ÿ.._ÿNaOH <-> _LNa,SO4laq} + ÿ H,O(1)

7. 25.0 mL of 0.10M nitric acid neutrali;eÿ4ÿL of bariums,

BALANCE! 'ÿ"ÿ HNOs (aq)+ -1-- Ba(O.), (aq)<-> ÿ Ba(NOs)z (aq)+ .ÿ_ÿH20 (1)

ofthe base.

J fr!o

Acid/Base STUDY GUIDE

This is due on 4/26/16 and must be completed in its entirety to earn +5 points on the test.

Acid and Base definitions:

1

8

10

15

D

m2

mmm

mmm

ACROSSi. Acid that completely ionizes in ÿater.3. Hydroxide containing compound.7. The compoundÿother than ÿater, produced from the neutralization of am acid and a base.9. The process used to neutralize acids and bases to determine the molarity of an uÿknoÿn concentration.i@. Base that only partially ionizes in water.12. proton (H+) donor13. The reaction with an acid and a base to produce a neutral solutioA of salt and ÿater.i4, protoR {H+) acceptorDown2, Hydrogeÿ containinÿ compound.4. Base the completely ionizes in ÿater.5. Substance that can be both an acid and a base.6. Acid that only partially ionizeÿ in water.8. Another term used for a basic substance.11. The stopping point in a titration ÿhen your solution has reached a neutral pH.24. Substance that produces OH- in solution15. Substance that produces H÷ in solution.

18

1. What are the properties of acids?

3. Label as Acid (A), Bÿse(B) or Salt(S)a. HCI

b. H3P04 /ÿ

c. HN02 'ÿ

2. What are the properties of bases?

d. LiOH

e. H2S03

f. H3P

g. Mg(OH)2 .ÿ

h. NaCI ,S

i. KN03

4, What are the products of the self-ionization reaction of water?

5. What does Kw stand for?

6. What is the value of Kw

I,Oo XtO-ÿq-7. Write the equation for Kw:

r vo ÿ= ÿ.ÿ + _3Y-- [ o .H - ,3 --- i, o o </o -ÿ'f

19

. Finish the equations:

poll= Iÿ

,+,o.= iq.

. What is the range for the pH scale?

t0

10. What is the equation used for a titration?

h-/_1_1,, Write a complete and balanced equation foI the following acid-base reaction:

Ca "ÿ ÿ0ÿ ÿa'ÿH3P04+ Ca(01-1)2 --)

=c,+ ==,o.,1 + II c l=

12. Calculate the co.ncentration of hydfochloric acid if 125.0nÿL of this acid is Neutralized by 60.OmL of 2.0M sodium

0ÿ :- ? hydroxide?ÿ:ÿ. ÿ, Oÿ ÿ I'IC' (aq, + I__L_NaOH (aq) ]ÿ -- ÿA ÿ'ÿ/b --L- HzO (1) + --L- NaC' (aq).ÿ -ÿ ÿÿ)_

13. Calculatethe,concentrationofsÿÿ' " . . " "c" Isneuj:ralizedbylÿMpotassi!ÿm"ÿ

. hydroxide? ! HzS04 (aq) + "5 KOH (aq) <-> _k KzSO4 (aq) + ÿ H20 (I) .

14. What is the m" olarity of 3.50 L of solution that contains 90.Og

cqol flÿot

20

LÿJ

tvlÿ

l Sÿ.owmanymoeso,.C aropro,ent n08,o, a0SM.CI(ÿ= ÿ0i ÿ, ÿ---- ÿt

Lm rÿ blTÿ

16. How any ÿ(.ÿ.ÿ]of 1ÿNO3 would be required to prepare 750 mL of a 0.5 M solution?

17. Complete the chart: t]ÿ," /ÿ:2 ÿ2ÿ_-remember Kw = [H+][OH-] and pH = -log H+] and pH + pO 0 /3ÿ L

Given Solve for Acidic, Basic, or Nÿ al?ÿÿMÿi

(A/B/N)

pH=7

pOH = 12.5 -kciAIc

6a¢1c.A-slÿilo

#.rr+ -ÿ ; i , q x l o-z aA

l, oo:ÿlÿ>-iq

i,o'i, lO-1o, oloqSl

21