Advertisements
Advertisements
Question
Define the following term:
Efflorescence
Advertisements
Solution
It is the phenomenon by which hydrated salts, on exposure to dry air, lose their water of crystallization and crumble to powder.
RELATED QUESTIONS
Identify the substance underlined, in the following case
A solid formed by reaction of two gases, one of which is acidic and the other basic in nature
State what would you observe when Washing Soda Crystals are exposed to the atmosphere
Write a balanced chemical equation for Action of dilute hydrochloric acid on magnesium sulphite.
Write a balanced equation for the preparation of the following salts:
Copper sulphate from Copper Carbonate.
Name three chemicals made from common salt (or sodium chloride).
Common salt is obtained from sea-water by the process of ______.
What happens when a concentrated solution of sodium chloride (brine) is electrolysed? Write the equation of the reaction involved.
Why is the electrolysis of a concentrated solution of sodium chloride known as chlor-alkali process?
What is meant by ‘a family of salts’? Explain with examples.
What is meant by ‘hydrated’ salts? Explain with examples.
P and Q are aqueous solutions of sodium chloride and sodium hydroxide, respectively. Which of these will turn:
- blue litmus red?
- red litmus blue?
A salt X when dissolved in distilled water gives a clear solution which turns red litmus blue. Explain the phenomenon.
How many molecules of water of crystallisation (per formula unit) are present in:
Copper sulphate crystals
You are asked to prepare hard water in your laboratory. Select a group from the following groups of salts, any salt of which you may dissolve in distilled water to obtain hard water.
(A) NaCl; Na2SO4; KCl
(B) NaCl; CaCl2; KCl
(C) CaCl2; CaSO4; MgSO4
(D) Na2SO4; CaSO4; MgSO4
Distinguish by a chemical test sodium chloride and sodium sulphide.
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.
Salt is ______ in nature.
An aqueous solution of a salt turns blue litmus to red. The salt could be the one obtained by the reaction of ______.
Select the correct answer from A, B, C, D and E.
A compound which in the aqueous solution state, is neutral in nature.
