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प्रश्न
What change will you observe if you test soap with litmus paper (red and blue)?
उत्तर
Since soap is basic in nature, it will turn red litmus blue. When soap is dissolved in water, the solution becomes alkaline due to the formation of alkali NaOH or KOH. The solution changes the colour of red litmus to blue, but it does not change the colour of blue litmus.
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संबंधित प्रश्न
In the neighbourhood of your school, hard water required for an experiment is not available. Select from the following group of salts available in your school, a group each member of which, if dissolved in distilled water, will make it hard:
(a) Sodium chloride, calcium chloride
(b) Potassium chloride, sodium chloride
(c) Sodium chloride, magnesium chloride
(d) Calcium chloride, magnesium chloride
Which of the following sets of materials can be used for conducting a saponification reaction for the preparation of soap?
(a) Ca(OH)2 and neem oil
(b) NaOH and neem oil
(c) NaOH and mineral oil
(d) Ca(OH)2 and mineral oil
A student took four test tubes P, Q, R and S and filled about 8 mL of distilled water in each. After that he dissolved an equal amount of Na2SO4 in P, K2SO4 in Q, CaSO4 in R and MgSO4 in S. On adding an equal amount of soap solution and shaking each test tube well, a good amount of lather will be obtained in the test tubes:
(a) P and Q
(b) P and R
(c) P, Q and S
(d) Q, R and S
State one use of saponification process.
Explain esterification reaction with the help of a chemical equation. Describe an activity to show esterification.
Why is common salt (sodium chloride) added during the preparation of soap?
What is a detergent? Name one detergent.
How is soap made? Write a word equation involved in soap making.
What is the advantage of detergents over soaps for washing clothes? Also state one disadvantage.
Give the reason of formation of scum when soaps are used with hard water.
Consider the following oils :
(I) Mobil oil
(II) Castor oil
(III) Turpentine oil
(IV) Kerosene
(V) Mustard oil
(VI) Coconut oil
Which of these can be used for prepartion of soap?
(a) I, II, III, VI
(b) II, V, VI
(c) II, III, V, VI
(d) II, III, VI
What is the difference between the chemical composition of soaps and detergents? State in brief the action of soaps in removing an oily spot from a shirt. Why are sops not considered suitable for washing where water is hard?
What is meant by 'surface activity'?
Explain why soap cannot be used in hard water.
Soaps were originally made from ______.
Water, coconut oil, and _______ are necessary for soap preparation.
Arrange the following statements in correct sequence
- Pour that solution into an empty matchbox, soap can be obtained after drying.
- Take the necessary quantity of water in a jar.
- Then add coconut oil drop by drop and stir it well.
- Add concentrated sodium hydroxide in the jar and allow it to cool.
- Try this soap to wash your hand kerchief.
- Cover your work area with old newspaper.
What are the three main constituents of soap?
How does soap clean clothes?
