ch 4 aqueous reactions.ppt

8/14/2019 CH 4 aqueous reactions.ppt

1/29

Aqueous

Reactions

Chapter 4

Aqueous Reactions andSolution Stoichiometry


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Aqueous

Reactions

Electrolytes

Substances that

dissociate into ions

when dissolved inwater.

Anonelectrolytemay

dissolve in water, but

it does not dissociateinto ions when it does

so.


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Aqueous

Reactions

Electrolytes and

Nonelectrolytes

Soluble ionic

compounds tendto be electrolytes.


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Aqueous

Reactions

Electrolytes and

Nonelectrolytes

olecular

compounds tend tobe nonelectrolytes,

e!cept "or acids and

bases.


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Aqueous

Reactions

Electrolytes

A stron# electrolyte

dissociates completely

when dissolved inwater.

A wea$ electrolyte

only dissociates

partially whendissolved in water.


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Aqueous

Reactions

Stron# Electrolytes Are%

Stron# acids

Stron# bases

Soluble ionic salts


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Aqueous

Reactions

&recipitation Reactions

'hen one mi!es ions

that "orm compounds

that are insoluble (ascould be predicted by

the solubility

#uidelines), a

precipitate is "ormed.


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Aqueous

Reactions

etathesis (E!chan#e) Reactions

etathesis comes "rom a *ree$ word thatmeans +to transpose

-t appears the ions in the reactant

compounds e!chan#e, or transpose, ions

A#N/ (aq)0 1Cl(aq)A#Cl(s)0 1N/ (aq)


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Aqueous

Reactions

olecular Equation

2he molecular equation lists the reactants

and products in their molecular "orm.

A#N/ (aq)0 1Cl(aq)A#Cl(s)0 1N/ (aq)


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Aqueous

Reactions

Net -onic Equation

2o "orm the net ionic equation, cross out anythin#that does not chan#e "rom the le"t side o" the

equation to the ri#ht.

2he only thin#s le"t in the equation are those thin#s

that chan#e (i.e., react) durin# the course o" the

reaction.

2hose thin#s that didn3t chan#e (and were deleted

"rom the net ionic equation) are called spectator ions.

A#0(aq)0 N/(aq)0 10(aq)0 Cl

(aq)

A#Cl(s)0 10

(aq)0 N/

(aq)


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Aqueous

Reactions

'ritin# Net -onic Equations

5. 'rite a balanced molecular equation.

6. 7issociate all stron# electrolytes.

/. Cross out anythin# that remains

unchan#ed "rom the le"t side to theri#ht side o" the equation.

4. 'rite the net ionic equation with the

species that remain.


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Aqueous

Reactions

Acids

2here are only seven

stron# acids8

9ydrochloric (9Cl) 9ydrobromic (9:r)

9ydroiodic (9-)

Nitric (9N/)

Sul"uric (96S4)

Chloric (9Cl/)

&erchloric (9Cl4)


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Aqueous

Reactions

:ases

2he stron# bases

are the soluble salts

o" hydro!ide ion8 Al$ali metals

Calcium

Strontium

:arium


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Aqueous

Reactions

Neutrali;ation Reactions

'hen a stron# acid reacts with a stron# base, the netionic equation is%

9Cl (aq)0 Na9 (aq) NaCl (aq)0 96 (l)

90 (aq)0 Cl (aq)0 Na0 (aq) 0 9(aq)

Na0

(aq)0 Cl

(aq)0 96 (l)

90 (aq)0 Cl (aq)0 Na0 (aq) 0 9 (aq)

Na0

(aq) 0 Cl

(aq) 0 96 (l)


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Aqueous

Reactions

Neutrali;ation Reactions

bserve the

reaction between

il$ o" a#nesia,#(9)6, and 9Cl.


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Aqueous

Reactions

!idationReduction Reactions

An o!idationoccurs

when an atom or ion

loseselectrons. A reductionoccurs

when an atom or ion

gainselectrons.


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Aqueous

Reactions

!idationReduction Reactions

ne cannot occur

without the other.


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Aqueous

Reactions

!idation Numbers

2o determine i" an o!idationreduction

reaction has occurred, we assi#n an

o!idation numberto each element in aneutral compound or char#ed entity.


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Aqueous

Reactions

!idation Numbers

Elements in their elemental "orm have

an o!idation number o"


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Aqueous

Reactions

!idation Numbers

Nonmetals tend to have ne#ative

o!idation numbers, althou#h some are

positive in certain compounds or ions.!y#en has an o!idation number o" =6,

e!cept in the pero!ide ion in which it has

an o!idation number o" =5.9ydro#en is =5 when bonded to a metal,

05 when bonded to a nonmetal.


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Aqueous

Reactions

!idation Numbers

Nonmetals tend to have ne#ative

o!idation numbers, althou#h some are

positive in certain compounds or ions.>luorine always has an o!idation number

o" =5.

2he other halo#ens have an o!idationnumber o" =5 when they are ne#ative? they

can have positive o!idation numbers,

however, most notably in o!yanions.


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Aqueous

Reactions

!idation Numbers

2he sum o" the o!idation numbers in a

neutral compound is


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Aqueous

Reactions

7isplacement Reactions

-n this reaction,

silver ions o!idi;e

copper metal.

Cu (s)0 6 A#0 (aq)Cu60 (aq)0 6 A# (s)


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Aqueous

Reactions

7isplacement Reactions

2he reverse reaction,

however, does not

occur.

Cu60 (aq)0 6 A# (s)Cu (s)0 6 A#0 (aq)!


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Aqueous

Reactions

Activity Series


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Aqueous

Reactions

olarity

2wo solutions can contain the samecompounds but be quite di""erent because the

proportions o" those compounds are di""erent.

olarity is one way to measure the

concentration o" a solution.

moles o" solutevolume o" solution in liters

olarity (M) @


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Aqueous

Reactions

sin# olarities in

Stoichiometric Calculations


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Aqueous

Reactions

2itration

2he analyticaltechnique in

which one can

calculate the

concentration o"a solute in a

solution.


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Aqueous

Reactions

2itration

ch 4 aqueous reactions.ppt

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