English

Give a scientific explanation. The hard water of a well becomes soft on adding washing soda to it. - Science and Technology

Advertisements
Advertisements

Question

Give a scientific explanation.

The hard water of a well becomes soft on adding washing soda to it.

Short Note

Solution

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.

\[\ce{MgCl2_{(aq)} + Na2CO3_{(s)} → MgCO3_{(s)} + 2NaCl_{(s)} }\]

shaalaa.com
  Is there an error in this question or solution?
Chapter 14: Substances in Common Use - Exercise [Page 162]

APPEARS IN

Balbharati Science and Technology [English] 9 Standard Maharashtra State Board
Chapter 14 Substances in Common Use
Exercise | Q 4. b. | Page 162

RELATED QUESTIONS

Name the sodium compound which is used for softening hard water.


Give two important uses of washing soda.


Name the metal whose carbonate is known as 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.


What is washing soda?


Describe how washing soda is produced starting from sodium chloride (common salt). Write equations of all the reactions involved.


What is meant by saying that washing soda has detergent properties?


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?


Write the name and formula of one salt each which contains:
ten molecules of water of crystallisation


How many molecules of water of crystallisation (per formula unit) are present in:

washing soda?


Write the chemical formula.

Washing soda


Answer the following question.
How is washing soda prepared from sodium carbonate? Give its chemical equation. State the type of this salt. Name the type of hardness of water that can be removed by it?


Correct the mistakes:

  1.  Washing soda is used for making cakes and bread soft, spongy.
  2. Calcium sulphate hemihydrate is used in textile industry for bleaching cloths.

Na2CO3.10H2O is ____________.


Correct the wrong statement given below:

Magnesium hydroxide is used in whitewashing buildings.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×