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प्रश्न
What are drying or desiccating agents? Give examples.
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उत्तर
These are substances which can readily absorb moisture from other substances without chemically reacting with them.
Examples:
Phosphorous pentoxide (P2O5), quick lime (CaO)
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संबंधित प्रश्न
Give two examples for Deliquescent substance.
Give one word for the following statement:
A substance which does not contain water .
Give one word for the following statement:
A property due to which a substance absorbs water without dissolving.
Complete the following table:
|
Common Name |
Chemical Name |
Formula |
Acid, base or salt |
Efflorescent, hygroscopic or deliquescent substance |
|
Solid caustic potash |
|
|
|
|
|
Quick lime |
|
|
|
|
|
Oil of vitriol |
|
|
|
|
|
Washing soda |
|
|
|
|
|
Solid caustic soda |
|
|
|
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Blue vitriol |
|
|
|
|
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”?
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?
What happens when MgSO4.7H2O is heated? Write the appropriate equation?
