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प्रश्न
State the methods by which hydrated salts can be made anhydrous.
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उत्तर
Hydrated salts can be converted to anhydrous substances by heating and also when exposed to dry air.
Example:
Glauber's salt becomes powdery anhydrous sodium sulphate when exposed to dry air.
\[\ce{Na2SO4.10H2O ->[dryair] NaSO4 + 10H2O}\]
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संबंधित प्रश्न
Give two examples of Crystalline anhydrous substances.
Give two examples for Deliquescent substance.
The sticky substance formed when soap is added to hard water is ______.
Give one word for the following statement:
Water molecules in loose chemical combination with other substances.
Give the names and formulae of two substances
Anhydrous substance
Match the substances in List I with the appropriate answer in List II.
| List I | List II |
| 1. Green vitriol | A: Permanent hardness in water |
| 2. Paint | B: Hygroscopic |
| 3. Magnesium chloride | C: Temporary hardness in water |
| 4. Magnesium bicarbonate | D: Heptahydrate |
| 5. Calcium oxide | E: Colloidal |
Differentiate between hydrated and anhydrous crystals with examples. State three defined changes that occur when hydrated copper sulphate is heated.
Match the following
| 1. | Blue vitriol | CaSO4.2H2O |
| 2. | Gypsum | CaO |
| 3. | Deliquescence | CuSO4.5H2O |
| 4. | Hygroscopic | NaOH |
A hot saturated solution of copper sulphate forms crystals as it cools. Why?
'A' is a blue coloured crystalline salt. On heating, it loses blue colour and to give 'B'. When water is added, 'B' gives back to 'A'. Identify A and B, write the equation.
