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प्रश्न
Define the following term:
Efflorescence
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उत्तर
It is the phenomenon by which hydrated salts, on exposure to dry air, lose their water of crystallization and crumble to powder.
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
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.
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.
Which of the following salt has a blue colour and why?
CuSO4.5H2O or CuSO4
What are the two main ways in which common salt (sodium chloride) occurs in nature?
Name the major salt present in sea-water.
Complete and balance the following chemical equation:
\[\ce{NaCl_{(aq)} + H2O_{(l)} ->[Electricity]}\]
The products of chloro-alkali process are ______.
Which of the following salts will give an aqueous solution having pH of almost 7?
Write the name and formula of one salt which contains:
Five molecules of water of crystallisation.
State one observation for each of the following :
Lead nitric is heated strongly in a test tube.
The pH values of three solutions A, B and C are given in the table. Answer the following questions:
| Solution | pH value |
| A | 12 |
| B | 2 |
| C | 7 |
- Which solution will have no effect on litmus solution?
- Which solution will liberate CO2 when reacted with sodium carbonate?
- Which solution will turn red litmus solution blue?
State what would you observe when :
Washing soda crystals are exposed to the atmosphere.
Distinguish by a chemical test sodium hydroxide solution and ammonium hydroxide solution.
Salts A, B, C, D and E undergo reactions (i) to (v) respectively. Identify the anion present in these salts on the basis of these reactions.
- When silver nitrate solution is added to a solution of A, a white precipitate, insoluble in dilute nitric acid, is formed.
- The addition of dilute hydrochloric acid to B produces a gas which turns lead acetate black on paper.
- When a freshly prepared solution of ferrous sulphate is added to a solution of C and concentrated sulphuric acid is gently poured from the side of the test tube, a brown ring is formed.
- When dilute sulphuric acid is added to D, a gas is produced which turns acidified potassium dichromate solution from orange to green.
- The addition of dilute hydrochloric acid to E produces effervescence. The gas produced turns lime water milky but does not affect acidified potassium dichromate solution.
Many salts absorb water from the atmosphere. This property is called:
What are hygroscopic substances?
An aqueous solution of a salt turns blue litmus to red. The salt could be the one obtained by the reaction of ______.
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:
Sodium zincate
