Advertisements
Advertisements
Question
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?
Solution
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
RELATED QUESTIONS
What causes the temporary and permanent hardness of water?
Discuss the principle and method of softening of hard water by synthetic ion-exchange resins.
What are the causes for
Permanent hardness
Name the substance which makes water temporarily hard
Explain with equation, what is noticed when permanent hard water is treated with
Slaked time
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 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.
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.
What are the causes of temporary hardness and permanent hardness of water?
Why does hard water not form lather with soap?
What is soft water?
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?
1000 g aqueous solution of CaCO3 contains 10 g of calcium carbonate. Hardness of the solution is ______.
