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प्रश्न
'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.
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उत्तर
Since ‘A’ is a blue coloured crystalline salt, it is CuSO4. 5H2O (Blue vitriol). On heating, it loses all five water molecules and becomes colourless anhydrous CuSO4.
\[\ce{\underset{\text{(A)}}{CuSO4.5H2O} ⇌[heating][cooling]\underset{\text{anhy. copper sulphate} Colourless (B)}{CuSO4 + 5H2O}}\]
When water is added ‘B’ gives back A.
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संबंधित प्रश्न
Give two examples for Deliquescent substance.
Water turns the colour of anhydrous copper sulphate .................
Give one word for the following statement:
A property due to which a substance absorbs water without dissolving.
Give the names and formulae of two substances
Anhydrous substance
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 |
|
|
|
|
|
Blue vitriol |
|
|
|
|
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:
Why is fused calcium chloride or cone, sulphuric acid used in a desiccator?
Select the correct word from the words in option to complete the sentence:
Efflorescence occurs when the vapour pressure of the hydrated crystals is ____ than the vapour pressure of the atmospheric humidity.
Name or state the following:
A liquid hydroscopic substance.
A hot saturated solution of copper sulphate forms crystals as it cools. Why?
