Chemical Effect of Electric Current and Its Applications

Chemical Effects of Electric Current: During rainy seasons you are often told to stay away from the electric poles? Have you ever wondered why is it so? This is because as the water flows continuously, the insulator turns into a conductor. As a result of this electricity can flow through your body. Let us now study the topic chemical effects of electric current in detail. To understand this better, explore the article.

Suggested Videos

 

Interactions with Electricity

Do liquids conduct electricity? Every one of you must be knowing what are conductors and what are insulators. The elements or materials which conducts electricity through them are something we call as conductors. Eg. Copper, Aluminium.  Also, the materials which do not allow the electricity to conduct through them are the insulators. Eg. Wood, Paper.

Let us see the conduction of electricity in liquids:

• Construct a circuit using two cells, an LED and connecting wires.
•  Immerse the two free ends of the wires into a beaker containing water or any liquid without touching each other, but also keep in mind that they must not be separated by a large distance.
• If the LED glows, the liquid conducts electricity and in case the LED does not glow, we can say the liquid does not conduct electricity.
• If the brightness of the LED glow is high, then those liquids are good conductors
• In case the brightness of the LED is low, it indicates that less current is going through those liquids and they are poor conductors of electricity.
• If the LED does not glow, it denotes that such liquids are insulators.

Different solutions or liquids conduct electricity differently. If we talk about the ordinary water, like the water from the tap or the well, these water contains minerals and salts. So these dissolved materials help to conduct them. But in the case of distilled water, there are no salts or minerals dissolved in it. As a result, the current will not flow in this case.

Chemical Effects of Electric Current

When an electric current is passed through a conducting solution, some chemical reaction takes place in the solution. This is among the chemical effects of electric current. For example, when some current is passed through water, water ionizes into H⁺ (aq) and OH^– (aq) ions, where H⁺ (aq) ions go towards the cathode to gain electrons and form H₂ whereas  OH^– (aq) ions go towards the anode to lose electrons and form O₂ molecules.

Some of the chemical effects of electric current are as follows :

• Bubbles of gas may be formed at electrodes.
• Deposits of metal may be seen on electrodes.
• Change of colour of solution may occur.

Electroplating

It is a process in which a layer of one metal is coated with another metal by electrolysis.

Electroplating Process for a Silver Spoon with Gold

• To coat a silver spoon with gold, we take the acidified solution of the metal to be coated (gold chloride with hydrochloric acid) as electrolyte and the article to be electroplated (silver spoon) is taken as a cathode.
•  Take a thick plate of the metal to be deposited (gold plate) as an anode.
•  The silver spoon is cleaned with a dilute acid solution to remove the oxide layer from its surface and washed in running water until it is free from the acid.
• The silver spoon thus cleaned is suspended in the acidified gold chloride solution (electrolyte) kept in a beaker.
•  A thick plate of gold (taken as an anode) is also suspended in the gold chloride solution.
• The circuit is completed using a battery and key.
•  Let the current pass through it for about 15 minutes and remove the electrodes from the solution.
•  Thus the silver spoon will look like a gold spoon.

Uses of Electroplating

• The most extensive use of gold plating is on jewellery and watch cases.
• Zinc coatings prevent the corrosion of steel articles.
• Nickel and chromium-coated articles are used in automobiles and household appliances.

Solved Examples for You

Question 1. The lightning conductor used in building protects the building by :

1. Dissipating the electric charge  away from the building
2. conducting the lighting safety to the ground
3. absorbing the electric charge
4. None of these

Solution: B is the correct option. The lightning conductor used in building protects the building by conducting the lighting safety to the ground.

Question 2. Buildings are more susceptible to a lightning strike because

1. They are higher than their surroundings
2. roofs of the building are wet in rainy seasons, and hence become good conductors of electricity
3. the top of the building is wet and acquires an opposite charge to a cloud passing over the top by the induction
4. None of these

Solution: D is the correct option. Buildings are more susceptible to a lightning strike because of all the above reasons.