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प्रश्न
The number of molecules of water of crystallisation present in washing soda crystals is ______.
पर्याय
five
two
ten
seven
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उत्तर
The number of molecules of water of crystallisation present in washing soda crystals is ten.
Explanation:
The chemical formula of washing soda is Na2CO3.10H2O. The water molecules that form part of a salt’s structure are called its water of crystallisation. Hence, the number of water molecules of crystallisation present in washing soda crystals is 10.
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संबंधित प्रश्न
From the list of the following salts choose the salt that most appropriately fits the
description is given in the following:
[AgCl, MgCl2, NaHSO4, PbCO3, ZnCO3, KNO3, Ca(NO3)2]
On heating this salt, a brown colored gas is evolved.
Give one word or a phrase:
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Copper sulphate crystals are always wet due to the presence of water of crystallisation in them.
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CuSO4.5H2O or CuSO4
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Copper sulphate crystals
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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
Give four substances which contain water of crystallization and write their common name.
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The salt ferric chloride is exposed to the atmosphere.
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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 | |
What is the pH of the acid which is used in the formation of common salt?
Salt is ______ in nature.
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