Intro to Electrolysis

7/21/2019 Intro to Electrolysis

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STARTER

• You have 10 min to carry on with theRedox equations sheet



Watch the demonstration



Electrolysis is splitting upsubstances using

electricity

(Lysis is latin for splitting



!hat is electrolysis"

• Electric current is used tobrea#down a substance made upof ions

• $n electrolyte is the name for

the substance being bro#en down



Electrolysis $pparatus

Cathode (%ve electrode

power supplyAnode

(&ve electrodeElectrolyte

+ve

-ve



Electrolysis $pparatus

Cathode (%ve electrode

Anode(&ve electrode

Electrolyte' thisis what will beelectrolysed

power supply



•ositive

•$node

•)egative

•*s•+athode

,on-t get stressed

in the exam'Remember $)*+



STARTER: Label the diagram!



1. Electrolytes contain ositive and negative ions.

. "#ring electrolysis$ ositive and negative electrodes are #t into the electrolyte.

%. The ositive electrode is called the anode.

&. The negative electrode is called the

cathode.'. The negative ions (called anions) are

attracted to the anode.

*. At the anode$ the negative ions lose

electrons to become atomsmolec#les.,. The ositive ions (called cations) are

attracted to the cathode.

. At the cathode$ the ositive ions gainelectrons to become atomsmolec#les

Act the sentences!



+ -

n+

n+

n+

n+

n+

n+

n+

/l-

/l-

/l-

/l-

/l- /l-

/l-

/l-

n+

positive electrode negative electrode

molten zinc

chloride (ions free

to move)

(anode) (cathode)e

-

e

-

e

-

e

-

Cl2

(g)

e

-

e

-

e

-

e

-

Zn

(s)



+ -

n+

n+

n+

n+

n+

n+

n+

/l-

/l-

/l-

/l-

/l- /l-

/l-

/l-

n+


molten zinc

chloride (ions free

to move)

(anode) (cathode)e

-

e

-

e

-

e

-

Cl2

(g)

e

-

e

-

e

-

e

-

Zn

(s)



+ -

n+

n+

n+

n+

n+

n+

n+

/l-

/l-

/l-

/l-

/l- /l-

/l-

/l-

n+


molten zinc

chloride (ions free

to move)

(anode) (cathode)e

-

e

-

e

-

e

-

Cl2

(g)

e

-

e

-

e

-

e

-

Zn

(s)



1. Electrolytes contain ositive and negative ions.

. "#ring electrolysis$ ositive and negative electrodes are #t into the electrolyte.

%. The ositive electrode is called the anode.

&. The negative electrode is called the

cathode.'. The negative ions (called anions) are

attracted to the anode.

*. At the anode$ the negative ions lose

electrons to become atomsmolec#les.,. The ositive ions (called cations) are

attracted to the cathode.

. At the cathode$ the ositive ions gainelectrons to become atomsmolec#les

Draw the sentence



At the electrodes

/athode (-)

(negative electrode)

• 0ositive ions go here

(cations).• As metal ions are

ositive$ they go tothe cathode.

• ons gain electrons. They are reduced andbecome ne#tralatoms.

Anode (+)

(ositive electrode)

• 2egative ions go here(anions).

• As non-metal ions arenegative$ they go to theanode.

• ons lose electrons.

They areoxidised

andbecome ne#tral atoms

(3hich react together to4orm molec#les).



/ommon ions

• Li+$ 2a+$ 5 +$

• 6g+$ /a+ $ n+

• /#+

$

/#+

$

7e+

$ 7e%+$

Al%+

• 28&+ (ammoni#m ion)

• 7-$ /l-$ 9r-$ -

• -$ S-

• 8- (hydro;ide ion)$ /%-$ 2%

-

(nitrate ion)$ S&- (s#lhate ion)



Compound Anode Cathode

.odium/romide

otassium

*odide+alcium

luoride

agnesium2xide

Lithium

+hloride



Tr#e or 7alse

• Electrolysis is the splitting of asubstance using electricity.

• The anode is negative.

• Anions are negative

• Aluminium oxide is found in bauxite.

• Cathode is negative.• Cations are negative.

Documents

Intro to Electrolysis