Conductivity of Water

Conductivity of Water

What is Conductivity?

Conductivity is nothing but the measure of capability of water to pass the flow of electric current. This ability of conductance is said to be directly proportional to concentration of the ions present in the water. The conductive ions in the solution usually come from the dissolved salts and also the inorganic materials like alkalis, sulfides, chlorides, along with some  of carbonate compounds.

The Compounds which dissolve into the ions are known as the electrolytes. The more number of ions present in the electrolyte, then the higher is the conductivity of water. In the similar way, fewer the number of ions present in water, then less conductive is the conductivity of water. De-ionized or distilled water can also act like a insulator due to the very low value of conductivity. Sea water is said to possess 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 form of ions called minerals etc. These ions are known to be responsible for the conduction of electric current in the water. Because, electrical current in water is transported by the ions present in them, and the conductivity is said to increase with the increase in the concentration of ions in them.

How conductivity is achieved?

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

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 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 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 as the temperature coefficient.

Practise This Question

The number of turns in primary and secondary windings of a transformer are 1000 and 100 respectively. If 200V dc voltage is impressed across the primary terminals, the voltage across secondary terminals is