ICSE ICSE Class 7 - CISCE Question Bank Solutions for Chemistry

Loading is basically speeding up _____.

Name the techniques used to separate a solid from its solution.

Explain the term ‘chemical reaction’ with special reference to – ‘reactants’ and ‘products’.

Represent the addition of dilute sulphuric acid to zinc by means of a chemical equation. State the function of the arrow between the reactants and products.

Give examples of exothermic reactions i.e. heat evolved in each of the following:

(a) reaction between a solid and a liquid
(b) reaction between two gases
Give two examples of exothermic reactions seen in everyday life.

Select the correct answer for the following options:

The black residue obtained on heating copper carbonate.

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The basic gas obtained when two gases react in presence of a catalyst and the reaction is exothermic.

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The gas obtained when potassium chlorate is heated in the presence of a catalyst.

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The gas which reacts with oxygen to give a neutral liquid.

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The pale blue precipitated obtained when copper [II] sulphate reacts with sodium hydroxide.

Give a word equation for the following reaction.

Two solids which combine on heating, to give a liquid.

Give a word equation for the following reaction.

Two gases which combine to give a solid.

Give a word equation for the following reaction.

A compound which on heating shows – colour change from brown to yellow.

Give a word equation for the following reaction.

A salt which reacts with ammonium hydroxide to give a reddish brown precipitate.

Give a word equation for the following reaction.

An exothermic reaction where both the reactants are gases, one of which is oxygen.

Give reason for the following:

Even though rusting is an exothermic reaction, the heat evolved when an iron nail rusts is unnoticeable.

Give reason for the following:

Electrolytic decomposition of water is a reaction involving change of state.

Give reason for the following:

A characteristic change of colour is seen when a piece of iron is added to copper [II] sulphate solution.

Give reason for the following:

The catalytic oxidation of sulphur dioxide to sulphur trioxide is represented by a double arrow {⇌} 
between the reactants and products, formed in the chemical reaction.

Name the following:

The products obtained during ‘photosynthesis’ – which is a chemical change.