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Question
What are the causes for
Permanent hardness
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Solution
The presence of sulphates and chlorides of magnesium and calcium makes water permanently hard.
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RELATED QUESTIONS
What do you understand by
Temporary 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 from water without 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.
Soap lathers well in hard water.
Give a reason for the following.
Hard water is not good for washing utensils.
What is soft water?
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?
