Bronsted-Lowry acids and bases titration curves

explainthatthereisabalanceof opposingreactions inchemical equilibriumsystems

2. determinequantitative relationships insimple equilibrium systems.

Key

Concepts:

The

following conceptsare developedinthis unit

and may

alsobe addressedinother unitsorinother courses.

The

intendedlevel and scope oftreatmentis defined

by

theoutcomes.

chemicalequilibrium systems

Bronsted-Lowry

acids

and

bases titration curves

conjugate pairsofacids

and

bases amphiproticsubstances

buffers indicators

Unit D: Chemical Equilibrium Focusing on Acid-Base Systems

©AlbertaEducation, Alberta,Canada

Chemistry 30 /67 (2007)

Studentswillexplainthatthereisabalance ofopposingreactions inchemical equilibrium systems.

SBhH

Specific

Outcomes

for

Knowledge

Studentswill:

30-D1

.Ik defineequilibrium andstatethecriteriathatapplytoachemical systemⁱⁿ equilibrium;

i.e.,closedsystem,constancy ofproperties,equal ratesof forward and reverse reactions

30-D

¹.2k identify,write andinterpretchemical equationsforsystemsatequilibrium

30-D1.3k

predict,qualitatively,using

Le

Chatelier's principle, shifts inequilibriumcausedby changesintemperature,pressure, volume, concentration orthe addition ofacatalyst

and

describe

how

thesechangesaffectthe equilibriumconstant

30-D

¹.4k define

K

ctopredicttheextentofthe reaction andwriteequilibrium-law expressions for givenchemical equations,usinglowest

whole-number

coefficients

30-D

¹.5k describe

Bronsted-Lowry

acids asprotondonors

and

basesasproton acceptors

30-D

1.6k write

Bronsted-Lowry

equations, including indicators,

and

predictwhetherreactantsor productsare favouredforacid-base equilibriumreactions formonoprotic and polyprotic acids

and

bases

30-D

1.7k identifyconjugatepairs andamphiprotic substances

30-D

^1.8k define abuffer asrelatively large

amounts

of a

weak

acidorbase anditsconjugate in equilibriumthatmaintain arelativelyconstant

pH when

small

amounts

ofacidor base are added.

Specific

Outcomes

for Science,

Technology and

Society (STS) (Nature

of

ScienceEmphasis)

Studentswill:

30-D

Lists explain thatthegoalofscience is

knowledge

aboutthe naturalworld (NS1)

• applyequilibriumtheories

and

principles toanalyze

a

variety

ofphenomena;

^e.g.,

carbon

dioxideescaping

from an open

bottle/can

of

carbonated beverage

-

role

of

^the oceansin thecarboncycle

-

solubility

of

^{oxygen gasin lakewater}

-

_acidprecipitation (deposition) - blood gasesindeep-seadiving

buffersin livingsystems

30-D

¹.2sts explainthat scientific

knowledge and

theoriesdevelop throughhypotheses,the collection ofevidence,investigation andthe abilitytoprovide explanations (NS2)

• research

how

equilibrium theories

and

principlesdeveloped

30-D

¹.3sts explainthatthegoalof technologyis toprovide solutions to practicalproblems (ST1)

[ICT

F2-4.4]

• analyze

how

equilibrium principleshave been appliedinindustrialprocesses; e.g.,

-

Haber-Bosch

process for producing

ammonia -

Solvay process for producing

sodium

carbonate - production

of

^methanol.

Note:

Some

oftheoutcomesaresupportedbyexamples. Theexamplesarewritteninitalicsanddo notformpart ofthe required

program

butareprovidedasanillustrationof

how

theoutcomes might bedeveloped.

General Outcome

1

Studentswillexplainthatthereis abalance ofopposingreactions inchemical equilibrium systems.

Specific

Outcomes

for Skills (Nature ofScience Emphasis)

Initiatingand Planning

Students will:

30-Dl.ls

formulate questionsabout observed relationships

and

plan investigationsofquestions, ideas, problems andissues

• predict variablesthatcan cause ashiftinequilibrium

(IP-NS3)

• designan experimentto

show

equilibrium shifts;e.g., colour change, temperature change, precipitation

(IP-NS2)

• describe proceduresforthe safe handling, storage

and

disposal ofmaterialsusedinthe laboratory,withreferenceto

WHMIS

and

consumer

productlabelling information

(IP-NS4)

• design

a procedure

toprepare

a

system capable

of

^buffering

(PR-ST2).

Performing

and

Recording Studentswill:

30-D1.2s

conductinvestigations into relationships

among

observablevariables

and

usea broad range oftools

and

techniques togather

and

record data

and

information

• perform an experimenttotest,qualitatively,predictions ofequilibrium shifts;

e.g., colourchange, temperaturechange, precipitation

and

gas production

(PR-NS3, PR-NS4, PR-NS5)

> • prepare

a

buj er

and

investigateitsrelativeabilities, with

a

control(i.e., water), to resista

pH ^change when a

small

amount of

^strongacid or strong baseis

added (AI-NS6).

Analyzing

and

Interpreting

Studentswill:

30-D1

.3s analyze dataand apply mathematical

and

conceptual

models

todevelop

and

assesspossible solutions

• write theequilibriumlawexpressionfora givenequation

(AI-NS1)

• analyze, qualitatively, the changesin concentrations

of

reactants

and

productsafteran equilibrium shift

(AI-NS6)

• interpretdatafromagraphto determine

when

equilibriumisestablished

and

to determinethe causeof astress onthe system

(AI-NS2, AI-NS6) [ICT

C6-4.1]

• interpret, qualitatively,titration curvesof monoprotic

and

polyprotic acidsand bases forstrong

acid-weak

base

and weak

acid-strongbase combinations,

and

identify buffering regions (AI-NS2).

Note:

Some

oftheoutcomesaresupportedbyexamples. Theexamplesarewritteninitalicsanddonotformpart of the required

program

butareprovidedasanillustrationof

how

theoutcomesmight bedeveloped.

Unit D:

Chemical

Equilibrium Focusing on Acid-Base Systems Chemistry 30 /69

©AlbertaEducation, Alberta,Canada (2007)

Students willexplainthat there isabalanceof opposing reactions inchemicalequilibrium systems.

Communication

and

Teamwork

Studentswill:

30-D1.4s

work

collaboratively inaddressingproblemsandapplythe skills and conventions of science in

communicating

informationand ideasandinassessingresults

•

work

cooperativelyto develop

an

illustration

and

explanation

of

reversiblereactions

(CT-ST2)

• use

advanced menu

features within

word

processingsoftwareto inserttables, graphs, text

and

graphics

when

developing

a group

report

on

equilibrium systems

(CT-SEC2) [ICTC

1-4.4]

Note:

Some

oftheoutcomesaresupportedbyexamples. Theexamplesarewrittenin italicsand do notformpart of therequired

program

butareprovidedasanillustrationof

how

theoutcomes might bedeveloped.

UnitD:

Chemical

Equilibrium Focusing

on

Acid-Base Systems Chemistry

30/71

©AlbertaEducation, Alberta,Canada

Students willdeterminequantitative relationshipsin simple equilibrium systems.

Specific

Outcomes

for

Knowledge

Studentswill:

30-D2.

Ik recalltheconcepts of

pH

and

hydronium

ion concentrationand

pOH

and hydroxide ion concentration,inrelation toacids

and

bases

30-D2.2k

define

K _w ,K

_a, K\> anduse these todetermine

pH, pOH, [H

3 +

]

and [OH]

of^acidic

and

In document problems and issues. By doing so, students become aware of the role of science in responding (Page 69-74)