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प्रश्न
Give a scientific explanation.
The hard water of a well becomes soft on adding washing soda to it.
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उत्तर
The hardness of hard water is due to the presence of chlorides and sulphates of calcium and magnesium. When washing soda (Na2CO3. 10H2O) is added to the hard water, Na2CO3 reacts with the chlorides and sulphates of calcium and magnesium and converts them to insoluble carbonate salts. This changes the hard water into soft water and thus makes it suitable for use.
\[\ce{MgCl2_{(aq)} + Na2CO3_{(s)} → MgCO3_{(s)} + 2NaCl_{(s)} }\]
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संबंधित प्रश्न
Give two important uses of washing soda.
What is the common name of (a) NaHCO3 and (b) Na2CO3.10H2O?
Fill in the following blank:
Chemical formula of washing soda is ..................
Fill in the following blank:
Sodium hydrogen carbonate is .................. soda whereas sodium carbonate is ................. soda.
State two properties and two uses of washing soda.
Write the formulae of sodium chloride and sodium carbonate.
Explain why an aqueous solution of sodium chloride is neutral but an aqueous solution of sodium carbonate is basic (or alkaline). Write chemical equations of the reactions involved.
Describe how washing soda is produced starting from sodium chloride (common salt). Write equations of all the reactions involved.
State whether an aqueous solution of washing soda is acidic or alkaline? Give reason for your answer.
Consider the following substances:
NaCl, Ca(OH)2, NaHCO3, NH3, Na2CO3, H2O, Cl2, CO2, CaSO4.2H2O, 2CaSO4.H2O, CaOCl2
Which four substances are utilised in the production of washing soda?
How many molecules of water of crystallisation (per formula unit) are present in:
washing soda?
The number of molecules of water of crystallization in washing soda is ______.
Correct the mistakes:
- Washing soda is used for making cakes and bread soft, spongy.
- Calcium sulphate hemihydrate is used in textile industry for bleaching cloths.
Chemical formula of washing soda is ____________.
Correct the wrong statement given below:
Magnesium hydroxide is used in whitewashing buildings.
The name of the salt used to remove permanent hardness of water is ______.
