How Electric Current Causes Chemical Reactions in Daily Life
We use electricity to run different appliances or other things such as doorbells, heaters, bulbs, fans, and many more. The chemical effect of electricity can be explained on these devices as well, and there are many ways to define chemical effects of electric current in brief. These devices make use of various effects of electric current like the heating effect and magnetic effect. Its chemical effect is another often-used effect of electric current. When electricity is passed through some specific liquids, chemical changes take place. Some of these changes are quite important to us.
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How is it Possible to Pass Electricity Through a Liquid? Let Us Look at It
Let us put two electrodes in the liquid and apply a fixed voltage across them. In a circuit, an electrode is a conductor being in contact with a nonmetallic thing, like liquid or gas. The electrode which is connected to the battery's positive terminal is known as the anode, whereas the electrode connected to the negative terminal is known as the cathode.
During rainy seasons we are often told to stay away from the electric poles. If we ever wondered why it is so, as the water flows continuously, the insulator turns into a conductor. Resultantly, electricity can flow through our bodies.
Thermal and Chemical Effects of Electric Current
The thermal and chemical effects of electric current are described briefly below. Let us have a look at these two factors.
Chemical Effects of Electric Current
This is a chemical effect of electricity that can be explained in terms of chemical properties. We all know that when an electric current passes through a solution, it ionizes and breaks down into ions. This is because of the chemical reactions that happen when an electric current passes through a solution. The electric current and its chemical effects are given below to identify easily. Based on the electrodes used and the nature of the solution, the following effects can be noticed in the solution:
A Change in the colour of the solution
Metallic deposits on the electrodes
Production of bubbles or a release of gas in the solution
Thermal Effects of Electric Current
Some of the thermal effects of electric current are given below.
Heating Effect - Let us look at the electricity and its heating and chemical effects thoroughly. The electric current makes heating of the electrical equipment. For example, the filament in a bulb gets heated up because of the electric current and glows, therefore.
Mechanical Effect - electric current can lead to the generation of mechanical energy in appliances. For example, motors and fans work due to this effect.
Magnetic Effect - electric current can lift upward to the magnetic field of a substance, which is a well-known chemical effect of electricity.
Chemical Effect - electric current can lead to the production of chemical reactions or chemical energy.
Application of Chemical Effect of Electric Current
Extracting Metals from Their Ores
Pure metals are extracted from the metal ores by the electrolysis process. Electricity is passed via the metal ores, and the ores get broken down into an ionic lattice, and thereby the metal obtains separately. For example, metals like magnesium, aluminium, potassium, calcium, and sodium are obtained from their ores in this way, which is a widely accepted application of chemical effect of electric current.
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Purification of Metals
The electrolysis method is used to purify metal by separating it from the impurities. The impure metal can be used as an anode that dissolves in the electrolyte solution first and later deposits on the cathode in the pure form. The metal impurities remain in the electrolyte solution only. Metals like aluminium, copper, and zinc are purified in this way.
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Production of Compounds
This electrolysis method is used for the production of some compounds, such as sodium hydrochloride. It is the easiest application of chemical effect of electric current.
Decomposition of Compounds
The electrolysis method is used to decompose a compound into its constituents. For example, water is decomposed with the process of electrolysis to obtain oxygen and hydrogen.
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Electroplating
Electroplating is a process where a layer of one metal is coated with another metal using the electrolysis method.
Electroplating Process for a Silver Spoon with Gold
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To coat the silver spoon with gold, we select the metal's acidified solution to be coated (gold chloride with the hydrochloric acid) as an electrolyte and the article (silver spoon) to be electroplated is selected as a cathode.
Then, take a thick plate of the metal (gold plate) to be deposited as an anode.
Now, the silver spoon should be cleaned with a dilute acid solution to remove the oxide layer from its surface and then washed in running water until it is free from the acid.
Thus, the cleaned silver spoon is suspended in the acidified gold chloride solution (electrolyte) kept in a beaker.
Also, the thick plate of gold (selected as an anode) is suspended in the gold chloride solution.
The circuit is then completed using a battery and a key.
Let the current pass through it for around 15 minutes and then remove the electrodes from the solution.
Therefore, the silver spoon will look like a gold spoon.
Uses of Electroplating
Some famous uses of electroplating are given as,
This is the most extensive use of gold plating used on watch cases and jewellery.
Zinc coating prevents the corrosion of steel articles.
Chromium and nickel-coated articles are used in household appliances and automobiles.
FAQs on Chemical Effects of Electric Current Explained
1. What are the chemical effects of electric current? Give some examples.
The chemical effect of electric current is the process where passing an electric current through a conducting liquid (an electrolyte) causes a chemical reaction. This phenomenon is also known as electrolysis. Key observable examples include:
- The formation of gas bubbles on the electrodes during the electrolysis of water.
- The deposition of a layer of metal onto another object, a process called electroplating.
- A change in the colour of the solution, indicating the formation of new substances.
2. What is electroplating and how is it used in everyday objects?
Electroplating is a practical application of the chemical effect of current where a thin layer of a desired metal is deposited onto another material using electricity. It is done to improve appearance, prevent corrosion, or add value. Common examples include:
- Chromium plating on car parts and bath taps for a shiny, scratch-resistant finish.
- Zinc coating on iron (galvanisation) to protect it from rusting.
- Gold or silver plating on jewellery made from less expensive metals to make it look attractive and premium.
3. Why is distilled water a poor conductor of electricity, and how can it be made conductive?
Distilled water is a poor conductor because it is very pure and lacks the free-moving charged particles (ions) needed to carry an electric current. To make it conductive, you can add a small amount of a substance that provides ions, such as:
- An acid (like lemon juice or sulphuric acid)
- A base (like sodium hydroxide)
- A salt (like common table salt)
4. What specific chemical changes occur when electricity is passed through a copper sulphate solution?
When an electric current passes through a copper sulphate (CuSO₄) solution, it dissociates into positive copper ions (Cu²⁺) and negative sulphate ions (SO₄²⁻). The positive copper ions are attracted to the negative electrode (cathode). Upon reaching the cathode, they gain electrons and get deposited on its surface as a layer of pure copper metal. This is a clear demonstration of both electrolysis and the principle behind electroplating.
5. How does the chemical effect of electric current differ from its heating effect?
The key difference lies in the type of change and the materials involved. The heating effect is a physical change where electrical energy converts into heat due to resistance, occurring in all conductors (solids and liquids). In contrast, the chemical effect is a chemical change that happens specifically in conducting liquids (electrolytes), causing the decomposition or formation of new chemical substances.
6. At a microscopic level, how do ions in a liquid facilitate the chemical effects of an electric current?
A conducting liquid contains freely moving positive ions (cations) and negative ions (anions). When electrodes from a battery are submerged, an electric field is created. This field forces the positive ions to move towards the negative electrode (cathode) and the negative ions to move towards the positive electrode (anode). This directed movement of ions constitutes the electric current in the liquid. When these ions reach the electrodes, they undergo chemical reactions by gaining or losing electrons, leading to the formation of new substances.
7. Why is an LED more effective than a traditional bulb for testing the conductivity of weak electrolytes like lemon juice?
An LED (Light Emitting Diode) is much more effective because it requires a very weak electric current to light up. Many liquids, such as lemon juice, tap water, or vinegar, are weak conductors and only allow a small current to flow. This current is often insufficient to heat the filament of a standard bulb to incandescence. Because an LED is highly sensitive, it provides a reliable indication of conductivity for a much wider range of substances.
8. Why is it dangerous to handle electrical appliances with wet hands, based on the principles of conductivity?
It is extremely dangerous because the tap water on our hands is a good conductor of electricity. Unlike pure water, tap water contains dissolved salts and minerals that provide free ions. When you touch an appliance with wet hands, the water forms a continuous conductive path from the appliance, through your body, to the ground. This allows a potentially lethal electric current to flow through your body, causing a severe electric shock.
9. What are the main observable signs that a chemical effect is taking place when current passes through a liquid?
There are three primary signs you can observe that confirm a chemical reaction is occurring due to an electric current:
- Formation of Gas Bubbles: Bubbles may appear on one or both electrodes, such as when hydrogen and oxygen gas are produced from water.
- Deposition of Metal: A new layer of metal may be seen coating the surface of the negative electrode (cathode).
- Change in Colour: The colour of the electrolyte solution may change, indicating that its chemical composition has been altered.
10. Can non-metals be electroplated onto other surfaces using a simple setup?
In a typical school-level experiment, electroplating involves the deposition of metal ions onto an electrode. Non-metals do not form positive ions (cations) in a solution that can be attracted to the negative electrode to get deposited. Therefore, using the standard process of electrolysis, you cannot electroplate a non-metal like sulphur or carbon onto a surface. The process is fundamentally designed for the reduction of metal cations into solid metal.
