chemical effects of electric current

Chemical effects of electric current

Conductors and Insulators

·     The materials which allow electric current to pass through them easily are called good conductors Of electricity.

For example, the metals such as copper and aluminium allow electricity to pass through them easily (Or conduct electricity), so they are good conductors Of electricity

·     The materials which do not allow electric Current to pass through them easily are called poor conductors Of electricity (or non-conductors Of electricity).The materials such as rubber, plastic and wood do not allow electric current to pass through them (do not conduct electricity), are poor conductors Of electricity

Liquids Also Conduct Electricity

·     The liquids that conduct electricity are solutions Of acids, bases and salts in water.

For example,

·     A solution Of sulphuric acid, hydrochloric acid, or any Other acid like vinegar or lemon juice , in water conducts electricity.

Note : Vinegar contains acetic acid and lemon juice contains citric acid.

·     A solution Of sodium hydroxide, potassium hydroxide. or any Other soluble base in water conducts electricity.

·     And a solution Of copper sulphate, common salt (sodium chloride), or any Other salt in Water also conducts electricity. 

Differences in the conduction of electricity by solids and liquids 

1.      In solids electricity is carried by electrons but in liquids, electricity is carried by ions . For example, in a solid like copper metal, electricity is carried by electrons but in a liquid like copper sulphate solution (CuSO₄ solution), electricity is carried by copper ions (Cu²⁺) and sulphate ions (SO ₄^2-)

2.      When electricity is passed through a solid, then no chemical change takes place but when electricity is passed through a liquid, then a chemical change takes place. For example when electricity is passed through a copper Wire, no chemical change takes place in it but when electricity is passed through acidified water, then a chemical change takes place in which water is decomposed into hydrogen and oxygen gases.

Note : The liquids which conduct electricity are called conducting liquids

The chemical changes which take place in conducting liquids on passing electric current through them are called chemical effects Of electric current.

Electrolyte

·     A liquid (or solution of a substance) which can conduct electricity is called an electrolyte. Thus , a conducting liquid is called an electrolyte.

·     A conducting liquid or electrolyte contains ions (positively charged ions and negatively charged ions).

·     The solutions of acids, bases and salts in water are electrolytes . 

Why salt solution is a good electrolyte

This is because when a salt dissolves, its dissociated ions can move freely in solution, allowing a charge to flow. The resulting solution will conduct electricity because it contains ions.

Why is sugar solution not a electrolyte ?

Glucose (sugar) readily dissolves in water, but because it does not dissociate into ions in solution, it is considered a nonelectrolyte; solutions containing glucose do not, therefore, conduct electricity.

Types of Electrolytes 

·     A Strong electrolyte is a liquid (or solution) which conducts electricity very well. A strong electrolyte is a very good conductor Of electricity because it contains a lot of ions in it. Some of the examples of strong electrolytes are : Sulphuric acid solution, Hydrochloric acid solution, Nitric acid solution, Sodium hydroxide solution, Potassium hydroxide solution, Common salt solution (Sodium chloride solution), Copper sulphate solution and Silver nitrate solution.

·     A weak electrolyte is a liquid (Or solution) which conducts electricity to a lesser extent. A weak electrolyte is a weak conductor of electricity because it contains lesser number Of ions. Some Of the examples Of weak electrolytes are : Vinegar (acetic acid solution), Lemon juice (citric acid solution), Carbonic acid solution, Ammonium chloride solution, Ordinary water (Tap water) and Rain water.

Why is solution of Hydrochloric acid with water a good electrolyte and solution of carbonic acid with water a weak electrolyte ?

Electrode

·      A solid electrical conductor through which an electric current enters Or leaves is called an electrode.

·      Electrodes are carbon rods Or metal rods depending upon where they are being used.

Types of Electrodes

·     Electrodes are Of two types : anode and cathode.

·     The electrode which is connected to the positive terminal Of the battery gets positively charged. The positively charged electrode is called anode.

·     The electrode which is connected to the negative terminal Of the battery gets negatively charged. The negatively charged electrode is called cathode.

Electrolytic Cell

An arrangement having two electrodes kept in a conducting liquid (or electrolyte) in a vessel is called an electrolytic cell. For example, if we keep two carbon electrodes in a beaker containing acidified water, it will be an electrolytic cell.

An electrolytic cell is used for carrying Out chemical reactions by passing an electric Current through the conducting liquid or electrolyte .

Note : A battery (Of cells) is used to pass an electric Current through the electrolyte taken in the electrolytic cell during the study Of chemical effects Of electric current.