Videos Related with pH Scale

Note on pH Scale

  • Note
  • Things to remember
  • Videos
  • Exercise
  • Quiz

The pH of a solution is defined as the measure of the H+ ions concentration present in the given solution. pH stands for potentiality of hydrogen. The higher the H+ ions in the solution, the more is the acidic solution whereas the higher the OH-ions in the solution, the more is the alkaline solution.

The pH value of a solution can be found out by the following two ways:

  1. By using universal indicator and pH colour chart
  2. By using pH meter

By using universal indicator and pH colour chart

The pH scale is a standard scale, which is used for measuring the approximate strength of an acid or an alkali solution.

The pH scale has ranged from 1 to 14. Acidic solutions have a pH value less than 7, while alkaline solutions have a pH value greater than 7. Distilled water has pH value 7 and is called neutral substance. Strong acids have pH value 1 or 2 while strong alkalis have pH value 13 or 14.

From the pH scale, we can say that higher the hydrogen ion concentration, lower is the pH value and vice versa.

The pH values of some substances are as follows:

S.N Substances pH
1.) Hydrochloric acid 1
2.) Apple, Vinegar and Carbonic acid 3
3.) Copper sulphate solution 5.5
4.) Water 7
5.) Human Blood 7.3
6.) Ammonia solution (NH4OH) 10
7.) Sodium Hydroxide (NaOH) 13

By using pH meter

pH meter is a man-made instrument which is used for measuring the pH value of a given solution directly in the numbers.

A solution of which pH value has to be measured is taken in a beaker and the pH rod is dipped in it. When the switch is on, the indicator of the pH meter deflects from its position and shows the pH value of the given solution.

Differences between pH paper and pH meter
It is strip of paper. It is a man made instrument.
It measures pH when dipped in a solution. It measures pH directly on a meter.

Importance of pH value

  1. pH value helps to understand the nature of solutions.
  2. It is used to find the pH value of soil condition in farming.
  3. It is used to know the pH value of water before water is supplied.
  4. It helps to compare acidity and alkalinity of solution.

  • The pH of a solution is defined as the measure of the H+ ions concentration present in the given solution.
  • The pH value of a solution can be found out by using universal indicator and pH colour chart and pH meter.
  • The pH scale is a standard scale, which is used for measuring the approximate strength of an acid or an alkali solution.
  • pH meter is a man made instrument which is used for measuring the pH value of a given solution directly in the numbers.
  • pH value helps to understand the nature of the solutions and to compare acidity and alkalinity of the solution.
.

Very Short Questions

The pH value 7 is neutral while an increasing pH value above 7 makes the solution alkaline and a decrease in the pH value makes it acidic. The solution with pH value 2 is more acidic as its pH value is lower than the other solution.

pH means the concentration of hydrogen ion (H+) present in a given solution and pH scale is the standard scale which is used to measure the hydrogen ion concentration present in a given solution.

pH meter is an instrument that determines the strength of acid and base directly.

The color of the pH value of the water is green.

The pH value of the compound formed by this reaction is 7 because sodium chloride and water both are neutral compound.

0%
  • pH stands for ______.

    possibility of hydrogen


    potentiality of hydrogen


    potentiality of helium


    peculiarity of hydrogen


  • A standard scale, which is used for measuring the approximate strength of an acid or an alkali solution, is called ______.

    pH value


    pH scale


    pH unit


    pH meter


  • Acidic solutions have a pH value ______.

    less than 7


    less than 14


    7


    more than 7


  • Alkaline solutions have a pH value ______.

    less than 7


    greater than 7


    greater than 1


    1


  • Neutral substances have a pH value _______.

    less than 7


    only 7


    greater than 1


    greater than 7


  • You scored /5


    Take test again

DISCUSSIONS ABOUT THIS NOTE

You must login to reply

Forum Time Replies Report

what is the ph value of men?


You must login to reply

ABHISHEK

why human blood is sour in taste although its ph value is 7.3


You must login to reply

Sina

Ph value of salt?


You must login to reply