Advertisements
Advertisements
Question
Name three methods by which hydrous substances can be made anhydrous.
Advertisements
Solution
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.
APPEARS IN
RELATED QUESTIONS
Give two examples of Crystalline anhydrous substances.
Give one word for the following statement:
A substance which does not contain water .
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”?
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.
Select the correct answer from the choice given in the options.
An anhydrous crystal _____.
Match the following
| 1. | Blue vitriol | CaSO4.2H2O |
| 2. | Gypsum | CaO |
| 3. | Deliquescence | CuSO4.5H2O |
| 4. | Hygroscopic | NaOH |
The molecular formula of green vitriol is MgSO4.7H2O.
Define Hydrated salt.
