Chemical Effects of Electric Current

An electrical tester is a simple piece of electronic test equipment used to determine the presence or absence of an electric voltage in a piece of equipment under test. It is also used to test whether a liquid allows electric current to pass through it or not.

Join the free ends of the tester together, for a moment, and check whether the bulb glows or not, if the bulb glows it means tester is working and if not it means tester is not working. In case it does not glow check that all connections are tight, or not.

Pour one table spoon of lemon juice in a plastic cap of discarded bottle, dip the end of tester into lemon juice, make sure that the tester should not more than 1 cm apart at also should not touch each other, we will observe the current flows in the circuit and bulb glows, this proves that lemon juice is good conductor.

This happens when current through the circuit is too weak to make the bulb glow

This is because current through the circuit is too weak so the filament of the bulb does not get heated sufficiently and it does not glow.

If weak current flows through the circuit then bulb in it will not glow. In order to detect weak current we use LED or may use another effect of electric current that is it produces magnetic effect also so we can use this property of electric current to detect weak current.

Under certain condition most of the materials can conduct electricity thus it is right to say poor conductors instead of bad conductors or insulators.

Distilled water is a poor conductor but if we add some salt in it the resulting salt solution is good conductor.

LED stands for Light emitting diode. It is a semiconductor light source, use to detect weak current in the circuit. There are two wires attached to a LED, one lead is slightly longer than the another one, the longer lead is always connected to the positive terminal of battery and shorter lead is connected to negative terminal of battery

the longer lead is always connected to the positive terminal of battery and shorter lead is connected to negative terminal of battery.

Tap water is not pure, it contains several amounts of mineral salts naturally dissolved in it , thus it is good conductor.

Water that we get from ponds and hand pumps is not pure, it contains several amounts of mineral salts naturally dissolved in it , thus it is good conductor.

Good conductor, becauseWhen we add kitchen salt (NaCl) to the distilled water the salt dissolves in water by splitting its molecules in ions:

H2O + NaCl --> H2O + (Na+) + (Cl-)

The NaCl molecules react to give ions. This happens because the NaClis a strong electrolyte. Solutions of strong electrolytes are good conductors of electricity because they contain a relatively high concentration of ions.

Poor conductor, because Sugar, as a non-electrolyte substance, does not produce ions when dissolved in water. A solution of sugar contains molecules of sucrose,but no ions. The absence of ions in a sugar aqueous solution makes it a non-electricity conductor fluid.

When electrodes are immersed in water and a current is passed bubbles of oxygen and hydrogen is produced.

One of the most common applications of the chemical effect of electric current is electroplating. In this process, there exists a liquid, usually called the electrolyte, through which current passes. Two electrodes, connected to the terminals of a battery with a switch in between, are inserted in the liquid. The electrode that is connected to the positive terminal of the battery is called the “anode,” and the other connected to the negative terminal is called the “cathode”. Electroplating is done in industries to have an anti-reactive coating on the parts of machines so that they do not react with the raw material, to have an anti-corrosive coating for the machines so that they do not get corroded, and a heat-resistivecoating for parts like boilers to resist the heat produced by the machinery.The process of electroplating is used for plating parts of vehicles with nickel and chromium, which protects them from corrosion.

One of the most common applications of the chemical effect of electric current is electroplating. In this process, there exists a liquid, usually called the electrolyte, through which current passes. Two electrodes, connected to the terminals of a battery with a switch in between, are inserted in the liquid. The electrode that is connected to the positive terminal of the battery is called the “anode,” and the other connected to the negative terminal is called the “cathode”. Electroplating is done in industries to have an anti-reactive coating on the parts of machines so that they do not react with the raw material, to have an anti-corrosive coating for the machines so that they do not get corroded, and a heat-resistivecoating for parts like boilers to resist the heat produced by the machinery.The process of electroplating is used for plating parts of vehicles with nickel and chromium, which protects them from corrosion.

Gold plating is one of the most common applications of electroplating in ornament-making.

In a circuit the induced current flowing through the coil is always such that it opposes the motion of the magnet. This process of producing induced current due to a varying magnetic field is called electro- magnetic induction.

Electrolysis: The passage of an electric current through a liquid causes chemical changes. This process is known as electrolysis.

Electrolytes: Conduction is possible only in those liquids which are at least partly dissociated into oppositely charged ions; such liquids are called electrolytes.Solutions of many inorganic chemical compounds (e.g. common salt, sulphuric acid, etc.) are examples of this type of liquid.

Voltameter: In electrolysis, the whole arrangement of electrodes, electrolyte and the vessel containing them is called a voltameter. In the case of the copper voltameter, which involves copper electrodes in copper sulphate solution, the net effect is that copper is dissolved off the anode and deposited on the cathode, with the electrolyte remaining unchanged.

The deflection through the compass needle shows that current is flowing through the wounded wire and hence through the circuit. The circuit is complete since free ends of the tester are dipped in the solution and the solution is certainly conducting solution.

Water may conduct electricity, if the electrical supply of the area is not shut off and water is poured over electrical appliances then electricity may pass through fire and may harm the fireman, thus In case of fire before the fireman used the water hoses, they shut off the main electrical supply of the area

The compass needle will defect more in case of sea water than drinking water because sea water contains more dissolved salt than the drinking water.

This is because rain water contains dissolved salts that makes it a conducting solution.

The substances which allow the electric current to pass through them are called conductors. Example metals like copper, aluminium. The substances which do not allow electric current to pass through them are called insulators, example : rubber, wood

The passage of an electric current through a conducting solution causes chemical reactions. Following are listed some of the chemical effects of electric current:

1. Bubbles of a gas may be formed on the electrodes.
2. Deposits of metal may be seen on electrodes.
3. Changes of colour of solutions may occur.

Infact, the reaction would depend on what solution and electrodes are used.

No, it is not at all safe for an electrician to carry out electrical repairs during heavy downpour. Rather, it is highly dangerous, because during heavy downpour there is a high risk of electrocution.

1. Take a filter paper and soak it with potassium iodide and starch solution.
2. Spread this filter paper on a metal sheet.
3. Now take two connecting wires and join them to the terminals of battery.
4. Attach the wire connected at positive end to plate.
5. Now write on the sheet wire attached to negative terminal.

We will see that wherever we write, blue coloured ink will appear. The reason for this is electrolysis of potassium iodide solution which produces iodine. Iodine on reaction with starch produces ink of blue colour.