(English Medium) ICSE Class 10 - CISCE Question Bank Solutions

Define the following term: 

Hygroscopy

What is deliquescence? What name is given to the compounds exhibiting such property?

Give four substances which contain water of crystallization and write their common name.

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.

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

Outline the steps required to convert hydrogen chloride to anhydrous iron (III) chloride. Write the equations for the reactions.

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?

State what would you observe when :
Washing soda crystals are exposed to the atmosphere.

State what would you observe when :
The salt ferric chloride is exposed to the atmosphere.

Write the colour of the following salts: Cuprous salts.

Write the colour of the following salt : Cupric salts.

Write the colour of the following salt : Aluminium salts.

Write the colour of the following salt : Ferrous salts.

Write the colour of the following salt : Ferric salts.

Write the colour of the following salt : Calcium salts.

A metal whose alloy finds use in the construction of aircrafts in the powdered form is added to sodium hydroxide solution. A colourless gas was evolved and after reaction was over, the solution was colourless.
(a) Name the powdered metal added to sodium hydroxide solution.
(b) Name the gas evolved.
(c) Name the salt present in the colorless solution.

On adding dilute ammonia solution to a colourless solution of a salt, a white gelatinous precipitate appears. This precipitate, however, dissolves on addition of excess of ammonia solution. Identify (Choose from Na, Al, Zn, Pb, Fe).

1. Which metal salt solution was used?
2. What is the formula of the white gelatinous precipitate obtained?

Fill in the blanks.
 Salts of ______ [normal / transition] elements are generally coloured.  From the ions K¹⁺, Cr³⁺, Fe²⁺, Ca²⁺, \[\ce{SO^2-_3}\], \[\ce{Mn^1-_4}\],\[\ce{NO^1_3}\] the ions generally coloured are ______.

One chemical test that would enable you to distinguish between the following pair of chemicals. Describe what happens with each chemical or state 'no visible reaction'.