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प्रश्न
How would you show that blue copper sulphate crystals contain water of crystallisation?
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उत्तर
Copper sulphate crystals (CuSO4.5H2O) are blue in colour. When copper sulphate crystals are heated strongly, they lose all the water of crystallisation and form anhydrous copper sulphate (which is white).
\[\ce{\underset{(Blue)}{\underset{Hydrated copper sulphate}{CuSO4*5H2O}} ->[Heat] \underset{(White)}{\underset{ Anhydrous copper sulphate}{CuSO4}} + \underset{(Goes away)}{\underset{Water}{5H2O}}}\]
Thus, on strong heating, blue copper sulphate crystals turn white (due to the loss of water of crystallisation).
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संबंधित प्रश्न
Identify the substance underlined, in the following case
A solid formed by reaction of two gases, one of which is acidic and the other basic in nature
How is common salt obtained from sea-water?
Explain how anhydrous copper sulphate can be used to detect the presence of moisture (water) in a liquid.
What is a salt?
What is meant by ‘a family of salts’? Explain with examples.
What is meant by ‘hydrated’ salts? Explain with examples.
The salt whose aqueous solution will have no effect on either red litmus or blue litmus is ______.
A salt is dissolved in water and the pH of this salt solution is measured with a universal indicator paper. If the pH of solution is less than 7, the salt is most likely to be ______.
P and Q are aqueous solutions of sodium chloride and sodium hydroxide, respectively. Which of these will turn:
- blue litmus red?
- red litmus blue?
When the concentrated aqueous solution of substance X is electrolysed, then NaOH, Cl2 and H2 are produced. Name the substance X. What is the special name of this process?
Give one example of a salt which gives an aqueous solution having:
pH more than 7
name two salts which are acidic.
name two salts which are basic.
Hard water required for an experiment is not available in a school laboratory. However, following salts are available in the laboratory. Select the salts which may be dissolved in water to make it hard for the experiment.
|
(1) |
Calcium Sulphate |
(2) |
Sodium Sulphate |
|
(3) |
Calcium Chloride |
(4) |
Potassium Sulphate |
|
(5) |
Sodium Hydrogen Carbonate |
(6) |
Magnesium Chloride |
(A) 1, 2 and 4
(B) 1, 3 and 6
(C) 3, 5 and 6
(D) 2, 4 and 5
Define the following term:
Efflorescence
Taking sodium carbonate as an example, give the meaning of the following terms:
Water of crystallization
State what would you observe when :
The salt ferric chloride is exposed to the atmosphere.
Sodium carbonate is a basic salt because it is a salt of a ____________.
The Salt Story
From: The New Indian Express 9 March 2021
The salt pans in Marakkanam, a port town about 120 km from Chennai are the third largest producer of salt in Tamil Nadu. Separation of salt from water is a laborious process and the salt obtained is used as raw materials for manufacture of various sodium compounds.
One such compound is Sodium hydrogen carbonate, used in baking, as an antacid and in soda acid fire extinguishers.
The table shows the mass of various compounds obtained when 1litre of sea water is evaporated.
| COMPOUND | FORMULA | MASS OF SOLID PRESENT /g |
| Sodium Chloride | NaCl | 28.0 |
| Magnesium Chloride | MgCl2 | 8.0 |
| Magnesium Sulphate | MgSO4 | 6.0 |
| Calcium Sulphate | CaSO4 | 2.0 |
| Calcium Carbonate | CaCO3 | 1.0 |
| TOTAL AMOUNT OF SALT OBTAINED | 45.0 | |
How many grams of Magnesium Sulphate are present in 135g of solid left by evaporation of sea water?
The chemical name of plaster of Paris is ______.
