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प्रश्न
Soap lathers well in hard water.
विकल्प
True
False
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उत्तर
Soap lathers well in hard water- false.
Correct statement:
Soap lathers well in soft water.
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संबंधित प्रश्न
What causes the temporary and permanent hardness of water?
Name the substance which makes water temporarily hard
Explain with equation, what is noticed when permanent hard water is treated with
Slaked time
Select the correct answer from the choice given in the options.
A substance which causes hardness in water _____.
Match the following.
| Universal solvent | Water pollutant |
| Hard water | Kills germs |
| Boiling | Ozonisation |
| Sterilization | Water |
| Sewage | Stomach ailments |
Give a reason for the following.
Hard water is not good for washing utensils.
What are the causes of temporary hardness and permanent hardness of water?
Why does hard water not form lather with soap?
The pleasant taste of drinking water is due to the presence of a dissolved substance which includes air, CO2, and minerals.
Take samples of water from different sources (like a tube well, a lake, a pond, or a river) and pour equal quantities of each sample of water into different test tubes. Measure the height of water in each test tube with a scale. Add one or two drops of liquid soap to each test tube. Shake each test tube five times and observe the height of the lather in each sample. Record your observations in the table. Which water is soft? Which water is hard? Can you say why?
