Home
Class 12
CHEMISTRY
Why do soaps not work in hard water ?...

Why do soaps not work in hard water ?

Text Solution

Verified by Experts

Soaps are sodium or potassium salts of long-chain fatty acids. Hard water contains calcium and magnesium ions. When soaps are dissolved in hard water, these ions displace sodium or potassium from their salts and form insoluble calcium or magnesium salts of fatty acids. These insoluble salts separate as scum.

This is the reason why soaps do not work in hard water.
Promotional Banner

Topper's Solved these Questions

  • CHEMICAL KINETICS

    NCERT|Exercise SOLVED EXAMPLE|1 Videos

  • COORDINATION COMPOUNDS

    NCERT|Exercise Exercise|41 Videos

Similar Questions

Explore conceptually related problems

Soaps do not work in hard water containing calcium and magnesium ions because

Both soap and detergent are some type of salts. What is the difference between them? Describe in brief the cleansing action of soap. Why do soaps not form lather in head water? List two problems that arise due to the use of detergents instead of soaps .

Is it true that soaps do not work well with hard water ?

In the laboratory of a school , the sample of hard water is not available " to study the comparative cleaning capacity of a sample of soap in soft and hard water". Which salt from the laboratory can be added to tap water to make it hard ? In the experiment how is cleaning capacity of soap compared ?

Soaps are the detergents used since long. Soaps used for cleansing purpose are sodium or potassium salts of long chain fatty acids such as stearic acid, palmitic acid. These cannot be used with hard water. Synthetic detergents are cleansing agents which have all the properties of soap but which actually do not contain any soap. These can be used both in soft water and hard water as they give foam even in hard water. Which of the following is called invert soap?

NCERT-CHEMISTRY IN EVERYDAY LIFE-Exercise
  1. Low level of noradrenaline is the cause of depression. What type of dr...

    Text Solution

    |

  2. What is meant by the term ‘broad spectrum antibiotics’ ? Explain.

    Text Solution

    |

  3. How do antiseptics differ from disinfectants ? Give one example of eac...

    Text Solution

    |

  4. Why are cimetidine and ranitidine better antacids than sodium hydrogen...

    Text Solution

    |

  5. Name a substance which can be used as an antiseptic as well as disinfe...

    Text Solution

    |

  6. What are the main constituents of dettol ?

    Text Solution

    |

  7. What is tincture of iodine ? What is its use ?

    Text Solution

    |

  8. What are food preservatives ?

    Text Solution

    |

  9. Why is use of aspartame limited to cold foods and drinks ?

    Text Solution

    |

  10. What are artificial sweetening agents ? Give two examples.

    Text Solution

    |

  11. Name the sweetening agent used in the preparation of sweets for a diab...

    Text Solution

    |

  12. What problem arises in using alitame as artificial sweetener ?

    Text Solution

    |

  13. How are synthetic detergents better than soaps ?

    Text Solution

    |

  14. Explain the following terms with suitable examples (i) cationic dete...

    Text Solution

    |

  15. What is the biodegradable polymer?Give an example of a biodegradable a...

    Text Solution

    |

  16. Why do soaps not work in hard water ?

    Text Solution

    |

  17. Can you use soaps and synthetic detergents to check the hardness of wa...

    Text Solution

    |

  18. Explain the cleansing action of soaps.

    Text Solution

    |

  19. If water contains dissolved calcium hydrogencarbonate, out of soaps an...

    Text Solution

    |

  20. Label the hydrophilic and hydrophobic parts in the following compounds...

    Text Solution

    |