Chemical Change
Chemical Change: Overview
This topic discusses the aspects of a chemical change. Various chemical reactions take place in a chemical change. The making of curd from milk is an example of this change. Related exercises are also provided.
Important Questions on Chemical Change
A student took a solution of copper sulphate in a beaker and put a clean iron nail into it and left it for about an hour.
Write a word equation for the chemical change, if any.
A student took a solution of copper sulphate in a beaker and put a clean iron nail into it and left it for about an hour.
Are these changes chemical in nature?A student took a solution of copper sulphate in a beaker and put a clean iron nail into it and left it for about an hour.
What changes do you expect?Give an example of a chemical reaction for the following situation:
Sound is produced.
Give an example of a chemical reaction for the following situation:
A gas is evolved.Give an example of a chemical reaction for the following situation:
A change in colour is observed.
Give two examples for the following case:
Chemical changes.Explain the following:
Bubbles are produced when acetic acid is added to a solution of sodium hydrogen carbonate.
Explain the following:
Lime water turns milky on passing carbon dioxide gas into it.
Write word equations for two chemical reactions with the help of materials given in the box.
[Air, copper sulphate, iron, vinegar, iron oxide, carbon dioxide, iron sulphate, copper, lime water, water]
Classify the following process into physical or chemical change:
Burning of crackers.
Classify the following process into physical or chemical change:
Digestion of food.
Anaerobic bacteria digest animal waste and produce biogas.
When a candle burns, both physical and chemical changes take place.
Which of the following statement is incorrect for a chemical reaction?
Which of the following is/are true when milk changes into curd?
(i) Its state is changed from liquid to semi-solid.
(ii) It changes colour.
(iii) It changes taste.
(iv) The change cannot be reversed.
Choose the correct option from below:
A chemical change may involve
Which of the following is a chemical change?
