Advertisements
Advertisements
Questions
Give reason for the following:
Hardness in temporary water can be removed by boiling, but hardness in permanent hard water cannot.
Temporary hardness in water can be removed by boiling.
Advertisements
Solution 1
Temporary hardness is due to the presence of bicarbonate of calcium or magnesium, on boiling bicarbonate decomposes to CO2, carbonate which is in soluble and can be filtered out. Where as permanent hard water contains [SO2]2- or Cl–– of calcium and magnesium, cannot be removed by boiling.
Solution 2
Temporary hardness in water is due to the presence of HCO3 of calcium or magnesium.
On boiling bicarbonate changes to carbonate which is insoluble in water and is filtered out, CO2 gas escapes and water becomes soft.
RELATED QUESTIONS
Give reason for It is difficult to cook in hills compared to plain.
Give two examples for Efflorescent substance.
Define the Soft water.
Define the Hard water.
Name the compound responsible for temporary hardness.
Temporary hardness of water can be removed by
Explain with equation, what is noticed when permanent hard water is treated with Washing soda.
Differentiate between Temporary & permanent hard water with suitable examples.
Give reason for the following:
Washing soda can be used to remove both temporary and permanent hardness in water.
Using given sample of temporary and permanent hard water, soft water, ordinary soap, detergent and washing soda how would you prove the advantage of detergent over soap.
Fill in the blank:
Hard and soft water can be distinguished using _____.
State the causes of hardness in water.
A sample of water is given in a trough. State how would you prove experimentally whether the given sample is hard water or soft water.
Permanent hardness of water is due to the presence of _______.
What are the methods of removing hardness of water?
Write a note on ion exchange.
