Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर
Differentiating temporary and permanent hard water
- Two unknown samples ‘A’ and ‘B’ containing temporary and permanent hard water are taken – separately in a trough or beaker.
- The water is boiled slowly, gases allowed to escape out, and then the water is filtered.
- Ordinary soap is rubbed by the hands – inside each filtered sample.
Observation
- One sample of water ‘A’ – lathers with soap.
- The sample of water ‘B’ – does not lather with
Result
- The boiled and filtered sample ‘A’ which lathers is temporary hard water – whose hardness is removed by boiling. Sample ‘B’ is permanent hard water – whose hardness cannot be removed by boiling.
APPEARS IN
संबंधित प्रश्न
What do you understand by
Temporary hard water
What do you understand by
Permanent hard water
What are the causes for
Permanent hardness
Name the substance which makes water permanently 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 remove temporary hardness from water without using a chemical compound?
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?
Both temporary & permanent hardness in water can be removed by addition of washing soda. Give balanced equations for the same.
Select the correct answer from the choice given in the options.
A substance which causes hardness in water _____.
Name or state the following:
A substance added to remove both temporary and permanent hardness in water.
Soap lathers well in hard 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?
The pleasant taste of drinking water is due to the presence of a dissolved substance which includes air, CO2, and minerals.
Which water is soft?
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?
