ICSE ICSE Class 7 - CISCE Question Bank Solutions for Chemistry

Statement given below is incorrect. Write the correct statement :

Moist oxygen causes rusting in carbon.

Write ‘True’ or ‘False’ in front of following statement.

Under laboratory conditions, the oxygen gas is insoluble in water. 

Write ‘True’ or ‘False’ in front of following statement.

Liquid oxygen is used for burning fuel in spaceships. 

Tick (√ ) the most appropriate answer.

The catalyst used in the preparation of oxygen from hydrogen peroxide is :

Tick (√ ) the most appropriate answer.

Sodium burns in oxygen with a flame which is :

Tick (√ ) the most appropriate answer.

When sulphur burns in oxygen, the colour of the flame is :

Write a fully balanced chemical equation for the decomposition of potassium nitrate crystals.

(a) Starting from hydrogen peroxide how is oxygen gas prepared in laboratory?
(b) What is the function of manganese dioxide?
(c) Write fully balanced equation for the liberation of oxygen from hydrogen peroxide.
(d) Why is the above method preferred to any other method?

State any four physical properties of oxygen gas.

Describe what you will observe and write fully balanced equation when the following is introduced in a jar of oxygen.

Burning magnesium

Write fully balanced equation for the following :

SO₂   +   H₂O  →

Write fully balanced equation for the following :

Na₂O   +   H₂O   →

State three uses of oxygen, other than artificial respiration.

Give tests for oxygen gas.

What is the number of electrons donated by a magnesium atom and number of electrons accepted by a sulphur atom during their chemical combination?

How many units of charge are developed on each atom?

What is the number of electrons after the transfer of electrons in magnesium and sulphur atoms.

Diagrammatically represent the transfer of electrons.

The most ductile metal is _______.

Write the molecular formulae of Magnesium nitride: