Name:_____________

Date:______________

The Conductivity of Aqueous Solutions Objectives Students will

• Determine generalization for conductivity of aqueous solutions • Determine relative conductivity of aqueous solutions with respect to concentration of ions

Materials

• 9V battery • Vinegar (CH3COOH) • LED light • 1.0M HCl • Electric wires • 1.0M and 0.1M NaOH • Distilled water • 1.0M and 0.1M NaCl • Pure methanol (CH3OH) • 1.0M sugar (C12H22O11)

Teacher Demo The teacher will show you how experiment is set up. Your task is to collect as many observations as possible in the data section. Record how brightly the light bulb glow. Data:

# Substance tested Result

1 Distilled water

2 Pure methanol

3 Vinegar

4 1.0M HCl

5 1.0M NaOH

6 0.1M NaOH

7 1.0M NaCl

8 0.1M NaCl

9 1.0M sugar

Apr .

11 C wed )

1, Start new SG

2, Conductivity Lab

HF : HI # 15 parts . . .

prediction

NO

Yes / NO

yes

yes

yes 1 NO

yes / NONO bk its lessthfn

Yes i no

NO MAY be [ ]

TS not high .

Yes

Questions: 1. The solution that caused the light bulb to glow is called conducting solution or electrolyte.

List the electrolyte being tested.

2. What types of compounds seem to conduct electricity?

3. The solution that did not cause the light bulb to glow is called non-conducting solution or non-electrolyte. List the non-electrolyte being tested.

4. What types of compounds seem to be unable to conduct electricity?

5. Compare the result 5 and 6 or 7 and 8 from the table. What relationship appears to exist between the concentration of ions in a solution and the conductivity of the solution?

The _________ (higher/lower) the ion concentration, the __________(higher/lower) conductivity.

Acid organicacid Ionic

• Vinegar ( Ctt 's

¥00) • Sodium chloride ( Nau )

Acid acid. Hydrochloric acid ( HH ) • Five Alive ( mixture )Base• Sodium hydroxide ( NAOH )

Acid

Base ( Metal OH )Ionic compound

• Distilled water ( HZO )Organic but not acid f

Not base

. Methanol ( CH30¥)Organic but not acid

. Sugar ( Cuthz 06 )

( C , H , 0 , Nis , Cl , F) ( ~ coat )Organic compound that is not acid

HF : SG examples ¥ front HI # 15

Solution(Chemistry(Notes(

( 1(

Introduction*to*Solution*Chemistry*What*is*solution?*

• ______________________(mixture(made(of(_____________(and(_______________.(

o E.g,(_______________(s),(_______________(((aq),(_______________(g)(

• Different(from(_______________(substance(like(water(l)(and(mercury(l)(

(What*is*solubility?*

• The(maximum(amount(of(_______________(that(can(dissolve(in(_______________(at(a(given(

temperature((e.g.,(of(unit(used(for(solubility(=(______,(______,______,(______)(

• _______________means(“dissolvable”((e.g.,(table(salt(is(soluble(in(water,(but(insoluble(in(oil)(

• When(you(have(a(solution(that(has(_______(amount(of(solute(dissolved(in(the(solvent,(the(

solution(is(_______________.(In(a(saturated(solution,(you(should(see(some(_____________(

material.(

• Solubility(depends(on(

1. __________________________________((

2. __________________________________((

3. __________________________________((

(e.g.,(A(spoonful(of(sugar(can(_____________(in(1L(of(water(at(room(temperature,(but(spoonful(of(

sugar(________________________(in(1L(of(oil(at(room(temperature.(

(Electrolyte*

Some(aqueous(solutions(can(conduct(electricity.(These(solutions(are(known(as(_____________.(When(

electrolyte(makes(a(complete(circuit(with(a(battery(and(a(light(bulb,(the(bulb(will(_____________.(This(

is(because(there(is(something(in(the(solution(that(can(carry(electric(charge(from(one(end(of(the(circuit(

to(the(other(end.(

(Guiding(question:(What(kind(of(solution(is(electrolyte?((Summary(from(the(mini(lab:(!(Solution(is(an(electrolyte(if(it:(

1. has(dissolved(_____________(compound((e.g.,(NaCl(!(_____________)(

C bigger ) ( smaller )Homogeneous solventsolute

steel Tap water air

pure a

solute solvent

g Kg 91mL MOYL

Miscible

Max

saturated undissowed

Nature and amount of solute

Nature and amount of solvent

Temperature ⇒ usuallyhotter solvent can

dissolve more solute

dissolve

Won't dissolve

electrolyteglow

A M r

*Iµ-E'slet

> electrolyte

Solution(Chemistry(Notes(

( 2(

2. has(dissolved(_____________(acid(or(base(e.g.,((HCl(!(_____________,(NaOH!((

_____________)(

3. has(dissolved(_____________(acid(ending(with(_____________((e.g.,(vinegar(=(acetic(acid=(

CH3COOH(!(_____________)(

(!(Solution(is(nonTelectrolyte(if(it:(

1. is(_____________)compound((e.g.,(CCl4)(

2. is(an(_____________)compound((e.g.,(C6H12O6(=(sugar,(CH3CH2OH(=(ethanol)(

a. Made(of(________________________.(

(What(makes(electrolyte(an(electrolyte?(!(_____________*

Note:*A(species(must(be(__________________(in(water(and(must(form(__________(to(make(an(

__________________.(*

(E.g.,(Practice(question:(Is(the(following(electrolyte?(Explain(your(answer.(

1. Ca(OH)2(!((

2. FeCl3(!((

3. CH3OH(!((

4. CH3CH2CH2CH2OH(!((

5. HCOOH(!((

6. PS2(!((

7. Ba(CN)2(!((

8. (Special)(CuS(!((

((Ion*Dissociation*and*Ion*Concentration*

*When(ionic(compounds(are(dissolved(in(solvent,(they(____________________________________.(

We(can(write(a(dissociation(equation(for(this.(As(usual,(the(equation(must(be(__________________.(

(General(form(of(dissociation(equation:((

((

Pay(attention(to(the(state!(

(((((((((((((((((((E.g.,(dissociation(of(KBr(s)( ( ( ((((((((E.g.,(dissociation(of(MgI2(s)((((

HFO