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प्रश्न
Define the following term:
Hygroscopy
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उत्तर
It is the phenomenon by which substances absorb moisture from air, but only sufficiently so as to become wet.
संबंधित प्रश्न
From the list of the following salts choose the salt that most appropriately fits the
description is given in the following:
[AgCl, MgCl2, NaHSO4, PbCO3, ZnCO3, KNO3, Ca(NO3)2]
On heating, this salt gives a yellow residue when hot and white when cold
The pH of a salt used to make tasty and crispy pakoras is 14. Identify the salt and write a chemical equation for its formation. List its two uses.
The salt prepared by the method of direct combination is _______.
Name the salt which is used as preservative in pickles, and in curing meat and fish.
Explain how anhydrous copper sulphate can be used to detect the presence of moisture (water) in a liquid
What happens when a concentrated solution of sodium chloride (brine) is electrolysed? Write the equation of the reaction involved.
What is meant by 'hydrated' and 'anhydrous' salts? Explain with examples.
When the concentrated aqueous solution of substance X is electrolysed, then NaOH, Cl2 and H2 are produced. Name the substance X. What is the special name of this process?
Give one example of a salt which gives an aqueous solution having:
pH less than 7
Consider the following salts:
Na2CO3, NaCl, NH4Cl, CH3COONa, K2SO4, (NH4)2SO4
Which of salts will give:
neutral solutions?
Write the name and formula of one salt each which contains:
two molecules of water of crystallisation
Explain ‘salt hydrolysis’
Hard water required for an experiment is not available in a school laboratory. However, following salts are available in the laboratory. Select the salts which may be dissolved in water to make it hard for the experiment.
|
(1) |
Calcium Sulphate |
(2) |
Sodium Sulphate |
|
(3) |
Calcium Chloride |
(4) |
Potassium Sulphate |
|
(5) |
Sodium Hydrogen Carbonate |
(6) |
Magnesium Chloride |
(A) 1, 2 and 4
(B) 1, 3 and 6
(C) 3, 5 and 6
(D) 2, 4 and 5
Answer the following questions below, relating your answers only to salts in the following list:
Sodium chloride, anhydrous calcium chloride, copper sulphate-5-water.
(i) What is the name given to the water in the compound copper sulphate-5-water?
(ii) If copper sulphate-5-water is heated, the water is driven off leaving anhydrous copper sulphate. What is the colour of anhydrous copper sulphate?
(iii) By what means, other than heating, you can dehydrate copper sulphate-5-water and obtain anhydrous copper sulphate?
(iv) Which one of the salts in the given list is deliquescent?
Name a colourless gas which bleaches.
One of the constituents of baking powder is sodium hydrogencarbonate. The other constituent is :
You are provided with the list of chemicals mentioned below in the box:
| Sodium hydroxide solution, copper carbonate, zinc, hydrochloric acid, copper, dilute sulphuric acid, chlorine, iron |
Using suitable chemicals from the list given, write a balanced chemical equation for the preparation of the salt mentioned below:
Ferric chloride
Select the correct answer from A, B, C, D and E.
A compound which in the aqueous solution state, is neutral in nature.
