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प्रश्न
Name three methods by which hydrous substances can be made anhydrous.
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उत्तर
Three methods by which hydrous substances can be made anhydrous are:
- Heating under vacuum.
- Direct heating.
- Heating in dry or hot air.
- By using dehydrating/desiccating agents such as warm concentrated sulphuric acid.
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संबंधित प्रश्न
What do you observe when Blue vitriol is heated?
Give the names and formulae of two substances
Anhydrous substance
The substance that can remove hydrogen and oxygen atoms in the ratio of 2:1(in the form of water) from the compound.
Complete the following table:
|
Common Name |
Chemical Name |
Formula |
Acid, base or salt |
Efflorescent, hygroscopic or deliquescent substance |
|
Solid caustic potash |
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|
|
|
Quick lime |
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|
|
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Oil of vitriol |
|
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|
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Washing soda |
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|
|
|
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Solid caustic soda |
|
|
|
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Blue vitriol |
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|
State the methods by which hydrated salts can be made anhydrous.
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.
Explain the following observation:
In the expression anhydrous copper sulphate, what is meant by “anhydrous”?
Name or state the following:
A liquid hydroscopic substance.
Differentiate between the following:
Deliquescent salt and hygroscopic salt
Match the following
| 1. | Blue vitriol | CaSO4.2H2O |
| 2. | Gypsum | CaO |
| 3. | Deliquescence | CuSO4.5H2O |
| 4. | Hygroscopic | NaOH |
