Conductivity of Water

Salt Water ConductivitySpecific ConductanceConductivity FAQs

Looking for other study material? arrow

The conductivity of water is a measure of the capability of water to pass electrical flow. This ability is directly dependent on the concentration of conductive ions present in the water. These conductive ions are originated due to inorganic materials such as chlorides, alkalis, carbonate and sulfides compounds and dissolved salts.

What is Electrical Conductivity?

Electrical conductivity is nothing but the measure of the capability of the material to pass the flow of electric current. Electrical conductivity differs from one material to another depending on the ability to let the electricity flow through them. Protons, electrons, and neutrons present in the material carry the current. Protons carry positive charge and each electron has a negative charge that it carries with it wherever it goes. The flow of electrons inside the material is referred to as the electric current. 

Electrical conductivity is denoted by the Greek letter ρ.

The  Electrical conductivity is the inverse of the resistivity and is given by

σ = 1/ρ

Where,

σ = electrical conductivity

ρ = resistivity

Conductivity of Water

This ability of conductance in water is directly proportional to the concentration of the ions present in the water.

The Compounds which dissolve into the ions are known as the electrolytes. The more the number of ions present in the electrolyte, then the higher is the conductivity of water. Similarly, fewer the number of ions present in water, then less conductive is the conductivity of water. Deionized or distilled water can also act as an insulator due to the very low value of conductivity. Seawater is said to possess a very high value of conductivity.

Pure water is said to be a bad conductor of electricity. Normal water is said to have impurities present in the form of ions called minerals etc. These ions are known to be responsible for the conduction of electric current in the water. Because, the electrical current in water is transported by the ions present in them, and the electrical conductivity is said to increase with the increase in the concentration of ions in them.


 
The conductivity of water is a measure of the capability of water to pass electrical flow. This ability is directly dependent on the concentration of conductive ions present in the water. These conductive ions are originated due to inorganic materials such as chlorides, alkalis, carbonate and sulfides compounds and dissolved salts.

What is Conductivity Of Water?

The degree to which water conducts or transmit, electricity or heat or sound in it is called conductivity of water. It is denoted by s or k.

Conductivity of Water Units:

The conductivity of water can be measured using multiple units. Some of them are:

Units
SI units Siemens per meter [S/m]
U.S units millimhos per centimeter [mmho/cm]

Value:

The value of conductivity of water for various types of water is given below:

Types of water Conductivity Value
Pure distilled and Deionized water 0.05 µS/cm
Seawater 50 mS/cm
Drinking water 200 to 800 µS/cm.
Rain or Snow water 2 to 100 µS/cm

You may also want to check out these topics given below!

Salt Water Conductivity

The saltwater is a good conductor of electricity. Its conductivity is greater than normal water. This is because salt molecules are made of sodium ions and chlorine ions (NaCl).

How is conductivity achieved?

Till now, we have learned that conductivity is purely the result of conductive ions present in the water. But how it actually conducts is the question. It can be simply explained by the following steps:

  • The ions present in the water conduct electricity because of the positive as well as negative charges present in them.
  • When the electrolytes tend to dissolve in the water, they get split into cation or positively charged and anions or negatively charged particles.
  • As dissolved substances tend to split in the water, the concentrations of positive and the negative charge remain the same.

This shows that, though the conductivity of the water increases with the addition of ions, it tends to remain electrically neutral.

What is Specific Conductance?

Specific conductance is the measurement of conductivity that is made at a temperature of 25° C. This is called the standardized method of achieving the conductivity. As the temperature of the water affects the conductivity reading, reporting the conductivity at about 25° C allows the data to be compared easily. The Specific conductance is basically reported in uS/cm at about a temperature measuring 25° C.

If the measurement of electrical conductivity is accomplished at a temperature of 25° C, then it can be called as the specific conductance. And, If the measurement is done at different temperatures and later corrected to the temperature of 25° C, then it is called the temperature coefficient.

Frequently Asked Questions – FAQs

Q1

How conductivity and salinity are related?

Conductivity is directly proportional to salinity. That is when salinity increases, the conductivity will also increase.

Q2

How is temperature related to the conductivity of water?

When the temperature is increased, the conductivity of the water will also increase.

Q3

What factors affect conductivity in the water?

The factors affecting the conductivity of water are-

  • The type of substance that dissolves in water.
  • Temperature.
  • The concentration of ions in solution.
  • Q4

    How is the conductivity of water tested?

    The electrical conductivity of water is measured by determining the resistance of the solution between two flat/cylindrical electrodes separated by a fixed distance. An alternating voltage is applied in order to avoid electrolysis. Thus, the resistance is measured by a conductivity meter.
    Q5

    What is the conductivity of distilled water?

    The distilled water conductivity is 0.05 µS/cm.

    Q6

    What is the conductivity of drinking water?

    The drinking water conductivity is 200 to 800 µS/cm.

    Hope you have learned about the electrical conductivity and conductivity of water. Stay tuned with BYJU’S for more interesting articles like thermal conductivity of metals, electrical resistance, etc. Also, register to “BYJU’S – The Learning App” for loads of interactive, engaging physics-related videos and an unlimited academic assist.

    Test Your Knowledge On Conductivity Of Water!

    Comments

    Leave a Comment

    Your Mobile number and Email id will not be published.

    *

    *

    DOWNLOAD

    App NOW