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प्रश्न
Using given sample of temporary and permanent hard water, soft water, ordinary soap, detergent and washing soda how would you remove temporary hardness from water without using a chemical compound?
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उत्तर
Temporary hardness can be removed by heating the hard water.
Experiment
Temporary hard water softened by heating
- Temporary hard water is taken in a beaker and heated
- After the gases escape out, the water is filtered through a filter paper.
- Ordinary soap is rubbed – inside the filtered solution.
Observation
- The boiled and filtered sample of – temporary hard water lathers readily with soap.
Result
- Temporary hard water can be – softened by heating.
\[\ce{\underset{\text{[in temporary hard water]}}{Ca(HCO3)2} ->\underset{\text{[ppt. filtered out]}}{CaCO3↓} +\underset{\text{[filtered water is soft]}}{CO2 + H2O}}\]
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संबंधित प्रश्न
Discuss the principle and method of softening of hard water by synthetic ion-exchange resins.
What do you understand by
Permanent hard water
What are the causes for:
Temporary hardness
Name the substance which makes water temporarily hard
How will you distinguish between temporary hard water and permanent hard water?
Using given sample of temporary and permanent hard water, soft water, ordinary soap, detergent and washing soda how would you distinguish between temporary hard water and permanent hard water?
Using given sample of temporary and permanent hard water, soft water, ordinary soap, detergent and washing soda how would you remove temporary hardness and permanent hardness from water using a chemical compound?
State what are synthetic detergents. Explain experimentally how you will determine the advantage of synthetic detergents over soap using a sample of hard water.
Name or state the following:
A substance added to remove both temporary and permanent hardness in water.
Soap lathers well in hard water.
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?
The pleasant taste of drinking water is due to the presence of a dissolved substance which includes air, CO2, and minerals.
Which water is hard?
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?
1000 g aqueous solution of CaCO3 contains 10 g of calcium carbonate. Concentration of the solution is ______.
