Notes for Voltaic Cell

1. Chemistry 2015 Chapter 6 : Electrochemistry
6.4 Voltaic Cells
1. A voltaic cell is an electrochemical cell that converts ________________ energy to
____________energy.
2. A simple voltaic cell is made by immersing ______________________________ of
metal in an ______________
3. Mechanism of simple Voltaic Cell :-
Anode (-ve) Cathode (+ve)
________ electropositive metal in ECS ________ electropositive metal in ECS
Metal atom ________ electron (ionised) to
form _____
Metal ion _______electron (discharged) to
form metal atom.
Anode become __________ Cathode become __________
4. Electrons flow from ____________ to ______________ through external circuit.
5. The flow of electric current is shown by the deflection of the ________________ needle.
6. Diagram shows a simple Voltaic Cell. A piece of zinc plate and copper plate are
immersed in copper(II) sulphate solution.
Example of Voltaic Cell
Anode (-ve) Cathode (+ve)
Zinc atoms ________ electron to form Zn2+
ions
Cu2+
_________ electron to form copper
metal
Half equation : Half equation :
Zinc electrode become ________ Copper electrode become _________
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2. Chemistry 2015 Chapter 6 : Electrochemistry
 ________________ metal is more electropositive than ________________ metal (at a
higher position in the ECS).
 ________________ becomes the _____________ terminal of the cell when the metal
____________ electrons to form ______________ ions.
 Hence, ______________ metal corrodes and become ______________
Half equation:
• Electrons accumulate at the surface of the zinc metal. This make zinc act as the
negative terminal (also known as the anode) of the cell.
 The electrons flow through the external circuit from the _________ (negative terminal or
anode) to the _________ (positive terminal or cathode)
 ____________ ions in the copper(II) sulphate solution accepting _______ electron to form
______________.
Half equation:
Overall equation:
Activity 1 : Draw a simple Voltaic Cell (Magnesium and Copper Plate immersed in Copper(II)
Sulphat solution). Then explain the process.
 ________________ metal is more electropositive than ________________ metal (at a
higher position in the ECS).
 ________________ becomes the _____________ terminal of the cell when the metal
____________ electrons to form ______________ ions.
 Hence, ____________metal corrodes and become ______________
Half equation:
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3. Chemistry 2015 Chapter 6 : Electrochemistry
• Electrons accumulate at the surface of the _________________metal. This make
_____________ act as the negative terminal (also known as the anode) of the cell.
 The electrons flow through the external circuit from the _________ (negative terminal or
anode) to the _________ (positive terminal or cathode)
 ____________ ions in the copper(II) sulphate solution accepting _______ electron to form
______________.
Half equation:
Overall equation:
6.5 Daniel Cell
1. Daniell cell is an example of voltaic cell.
Daniel Cell Daniel Cell
(using a porous pot) (using a salt bridge)
• Electrodes  _______ (anode / _________ electrode)
________ (cathode / __________ electrode)
• At :-
i) anode : the electrode ____________ by _____________ electrons and become
_______________
ii) cathode : the ____________ (lower position in ECS) attracted to cathode and
____________ discharged by ______________ electrons.
• The two solutions are separated by the porous pot/salt bridge
• The function of porous pot / salt bridge :-
i) prevent the two electrolytes from ______________
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4. Chemistry 2015 Chapter 6 : Electrochemistry
ii) to allows the movement of _________ so that the circuit is complete
• A salt bridge is made from a filter paper soaked in a saturated solution
that will not react with the two electrolytes. The common electrolyte used are or a solution
of ___________ or ___________ salts solution.
2. Mechanism of Daniel Cell :-
Anode Cathode
_______ releases electrons ____ ions _________ electrons
Half equation : Half equation :
Overall Equation :
___________ become ________ ___________ becomes __________
The concentration ________ ions in copper (II) sulphate solution _____________.
The blue colour of the solution become ____________.
Activity 2 :
(a) State the name of cell above
(b) State the energy change occurred
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5. Chemistry 2015 Chapter 6 : Electrochemistry
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
Which electrode act as :
i) negative electrode (anode) : ______________________
ii) positive electrode (cathode) : ____________________
(i) What is the expected observation at the zinc plate
(ii) Write a half equation for the reaction that occurs at the zinc plate
(i) What is the expected observation at the copper plate
_________________________________________________________________________
(ii) Write a half equation for the reaction that occurs at the copper plate
Write the formulae of all ions present in copper(II) sulphate solution.
_________________________________________________________________________
What happen to the intensity of blue colour of copper(II) sulphate solution
Draw arrows (→) to show the direction of the electrons flow in the diagram above.
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6. Chemistry 2015 Chapter 6 : Electrochemistry
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
Which electrode act as :
i) negative electrode (anode) : ______________________
ii) positive electrode (cathode) : ____________________
(i) What is the expected observation at the zinc plate
(ii) Write a half equation for the reaction that occurs at the zinc plate
(i) What is the expected observation at the copper plate
_________________________________________________________________________
(ii) Write a half equation for the reaction that occurs at the copper plate
Write the formulae of all ions present in copper(II) sulphate solution.
_________________________________________________________________________
What happen to the intensity of blue colour of copper(II) sulphate solution
Draw arrows (→) to show the direction of the electrons flow in the diagram above.
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