Effect of adding Sodium Chloride on the Electrical Conductivity of Distilled Water

Our Objective 

To demonstrate that a higher resistance is offered by distilled water and a low resistance when Sodium Chloride is added to it. 


The Theory


An electrode is an electric conductor that is typically made of metal and is used as one of the two terminals of a medium that conducts electricity. The medium can be a solid, gas, or vacuum or an electrolytic solution like in a storage battery. The electrode that receives electrons is known as the anode and is labelled as positive, whereas the electrode from which electrons emerge is known as the cathode and is designated as negative. The anode is referred to as the plate in an electron tube, and the conducting components that control the flow of electrons inside the tube are referred to as electrodes. The process of transmitting electric current through an electrolyte’s solution to decompose it is known as electrolysis.  

Electric circuit: 

Electric circuit: A way for current to travel. A battery or generator, a device that provides energy to the charged particles that make up the current, a device that uses current, such as a lamp, an electric motor, or a computer, and the connecting wires or transmission lines make up an electric circuit. Several categories are used to categorise electric circuits. One-way current only flows through a direct-current circuit. As in most residential circuits, an alternating-current circuit transports current that pulses back and forth repeatedly every second. 


Electricity's resistance is the characteristic of an electric circuit or a component of a circuit that converts electrical energy into thermal energy in the presence of an opposing electric current. Resistance is caused by the current carrying charged particles colliding with the fixed particles that make up the conductors' structure. Resistivity of a wire depends upon the material. The unit of resistance is ohms. 

Resistance is encountered by an electron as it passes through the external circuit's wires and loads. The obstacle to the flow of charge is resistance. An electron cannot travel in a straight line from one terminal to the next.  

Instead, a zigzag path is created by several collisions with stationary atoms in the conducting substance. The movement of the electrons is hampered by resistance. Resistance prevents the passage of charge, whereas the electric potential difference between the two terminals promotes it. The combined influence of these two factors determines the rate at which charge flows from terminal to terminal. The resistances in the higher range are made of carbon. 

One crucial element in electrical characteristics is resistance. To comprehend how each circuit part behaves, it is crucial to know the resistance of the circuit. Other electrical quantities can also be measured by measuring resistance. They are divided into three categories based on the resistance value, 

  1. Low Resistance - Low resistance is defined as resistance as significant as 1Ω or less. 
  2. Medium Resistance: Resistances with values between 1Ω and 100Ω are referred to as medium resistances. 
  3. High Resistance - High resistance is defined as resistance as significant as 100kΩ and above. 


Learning Outcomes 

  • Students understand the concept of electrodes. 
  • Students understand the topic based on electric circuit.
  • Students understand the concept of resistance and its categories.