Chemistry Practicals For Class IX (Science Group) - Experiment No. 7: To test the passage of an electric current through electrolytic and non-electrolytic solutions.

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EXPERIMENT NO.7

TO TEST THE PASSAGE OF AN ELECTRIC CURRENT THROUGH 7 ELECTROLYTIC AND NON.ELECTROLYTIC SOLUTIONS.

APPARATUS:

• Two copper strips
• Electrolytic pot or beaker
• Connecting wire
• Bulb holder
• Ammeter
• Dry cell or a battery
• Hanger
• Torch bulb
• Key

CHEMICALS:

• Copper sulphate solution
• Sodium hydroxide solution
• Benzene
• Sodium chloride solution
• Sugar solution

THEORY:

ELECTROLYTES:
Those liquids which conduct electricity are called electrolytes .e.g. solutions of copper sulphate, sodium chloride, sodium hydroxide etc.

NON- ELECTROLYTES:
Those liquids which do not conduct electricity are called non electrolytes .e.g. benzene, sugar solution etc.

METHOD:

• Put given solution (sodium chloride solution) into the electrolytic pot.
• Connect one copper strip to the positive terminal of the cell (battery) through a bulb and a key.
• Connect the second electrode (copper plate) to the negative terminal of the battery through an ammeter.
• Now hang copper strips (electrodes) by a hanger into the pot of given solution.
• Complete the circuit by inserting key in key hole.
• If the current flows across the solution between the two electrodes, the bulb will start glowing and ammeter show deflection. This indicate that the given substance is an electrolyte and if the current does not flow across the solution between the two electrodes, the bulb will not glow and ammeter show no deflection. This indicates that the given substance is a non - electrolyte.
• Repeat the experiment by taking different solutions. Wash electrodes with distilled water for each test.

S.No.	Name Of Solution	Condition Of Bulb Glowing / Not Glowing	Condition Of Ammeter Deflecting / Not Deflecting	Nature Of Solution Electrolyte / Non electrolyte
1	Sodium chloride solution	Glowing	Deflecting	Electrolyte
2	Caustic soda solution	Glowing	Deflecting	Electrolyte
3	Sugar solution	Not Glowing	Not Deflecting	Non-electrolyte
4	Ethyl alcohol	Not Glowing	Not Deflecting	Non-electrolyte

RESULT:
1. Sodium chloride and Caustic soda solutions are electrolytes.
2. Sugar and Ethyl alcohol solutions are non-electrolytes.

REASON:
Glowing of bulb and deflection of ammeter in case of Sodium chloride and Caustic soda solutions indicate that these solutions conduct electricity, hence these solutions are electrolyte. The bulb will not glow and ammeter will not deflect in case of Sugar and Ethyl alcohol solution. This Indicate that these solutions are non-electrolytes.

PRECAUTIONS:

• Connections should be tight.
• Electrodes should be separated from each other in electrolytic pot.
• Dilute solutions should be used.
• The electrodes should be washed with distilled water after each test.

Special Thanks to Sir Sajjad Akber Chandio