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प्रश्न
Fill in the blank
___________ is the phenomenon by which hydrated salts on exposure to dry air, lose their water of crystallization and crumble to powder.
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उत्तर
Efflorescence is the phenomenon by which hydrated salts on exposure to dry air lose their water of crystallisation and crumble to powder.
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संबंधित प्रश्न
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.
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
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?
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 have no effect on litmus solution?
Define the following term:
Efflorescence
Answer the questions below relating your answers only to salts in the following list: Sodium chloride, anhydrous calcium chloride, copper sulphate-5-water?
- What name is given to the water in the compound copper sulphate-5-water?
- If copper sulphate-5-water is heated, anhydrous coppersulphate is formed. What is its colour?
- By what means, other than healing, could you dehydrate copper sulphate-5-water and obtain anhydrous coppersulphate?
- Which one of the salts in the given list is deliquescent?
Distinguish by a chemical test sodium hydroxide solution and ammonium hydroxide solution.
What are hygroscopic substances?
