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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, a brown colored gas is evolved.
State whether the following statement is true or false:
Copper sulphate crystals are always wet due to the presence of water of crystallisation in them.
Name three chemicals made from common salt (or sodium chloride).
Name the salt which is used as preservative in pickles, and in curing meat and fish.
Complete and balance the following chemical equations:
`NaCl + NH_3 + H_2O +CO_2`→
What is meant by 'hydrated' and 'anhydrous' salts? Explain with examples.
A salt whose aqueous solution will have a pH of more than 7 will be:
(a) K2CO3
(b) K2SO4
(c) NaCl
(d) NH4Cl
The metal salt A is blue in colour. When salt A is heated strongly over a burner, then a substance B is eliminated and a white powder C is left behind. When a few drops of a liquid D are added to powder C, it becomes blue again. What could be A, B, C and D
The pH values of three solutions A, B and C are given in the table. Answer the folloiwng questions:
| Solution | pH value |
| A | 12 |
| B | 2 |
| C | 7 |
Which solution will liberate CO2 when reacted with sodium carbonate?
Define the following term:
Efflorescence
What is deliquescence? What name is given to the compounds exhibiting such property?
Taking sodium carbonate as an example, give the meaning of the following terms:
Water of crystallization
Taking sodium carbonate as an example, give the meaning of the following terms:
Anhydrous
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?
Distinguish by a chemical test sodium carbonate and sodium sulphite.
Which of the following is not an acidic salt?
The Salt Story
From: The New Indian Express 9 March 2021
The salt pans in Marakkanam, a port town about 120 km from Chennai are the third largest producer of salt in Tamil Nadu. Separation of salt from water is a laborious process and the salt obtained is used as raw materials for manufacture of various sodium compounds.
One such compound is Sodium hydrogen carbonate, used in baking, as an antacid and in soda acid fire extinguishers.
The table shows the mass of various compounds obtained when 1litre of sea water is evaporated.
| COMPOUND | FORMULA | MASS OF SOLID PRESENT /g |
| Sodium Chloride | NaCl | 28.0 |
| Magnesium Chloride | MgCl2 | 8.0 |
| Magnesium Sulphate | MgSO4 | 6.0 |
| Calcium Sulphate | CaSO4 | 2.0 |
| Calcium Carbonate | CaCO3 | 1.0 |
| TOTAL AMOUNT OF SALT OBTAINED | 45.0 | |
How many grams of Magnesium Sulphate are present in 135g of solid left by evaporation of sea water?
The acid reacts with a base to form a neutral product called ______.
How is normal salt obtained? Give a suitable reaction.
