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प्रश्न
Differentiate between ‘hydrated’ & ‘anhydrous’ crystals. Give the chemical formula of – the following hydrated crystals -
(a) Washing soda
(b) Gypsum
(c) Blue vitriol
(d) Epsom salt
(e) Glauber’s salt.
State which crystal from (a) to (e) is a pentahydrate.
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उत्तर
| Hydrated crystals | Anhydrous crystals |
| Hydrated crystals contain a definite number of water molecules (as water of crystallisation) in a loose chemical combination with the crystal. | Anhydrous crystals do not contain any definite number of water molecules in loose chemical combinations with the crystal. |
| E.g., CuSO4.5H2O | E.g., KNO3 |
The formula of hydrated crystals:
(a) Washing soda: Na2CO3.H2O
(b) Gypsum: CaSO4.2H2O
(c) Blue vitriol: CuSO4.5H2O
(d) Epsom salt: MgSO4.7H2O
(e) Glauber’s salt: Na2SO4.10H2O
Blue vitriol [CuSO4.5H2O] is a pentahydrate.
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संबंधित प्रश्न
Define water of crystallization. Give two examples with formulae.
Water turns the colour of anhydrous copper sulphate .................
The sticky substance formed when soap is added to hard water is ______.
State the methods by which hydrated salts can be made anhydrous.
Complete the statement by filling the blank with the correct word from the option.
Hygroscopic substance absorb moisture from the atmosphere & _______their original state.
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 |
Explain the following observation:
In the expression anhydrous copper sulphate, what is meant by “anhydrous”?
Explain the following observation:
Why is fused calcium chloride or cone, sulphuric acid used in a desiccator?
'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.
What happens when MgSO4.7H2O is heated? Write the appropriate equation?
