Give an example of a chemical reaction for each of the following situations:
(a) A change in colour is observed.
(b) A gas is evolved.
(c) Sound is produced
Give two examples for each of the following cases:
(a) Physical changes which are reversible.
(b) Physical changes which are not reversible.
(c) Chemical changes.
Give two examples for each of the following cases:
(a) Physical changes which are reversible.
(b) Physical changes which are not reversible.
(c) Chemical changes.
Explain the following:
(a) Lime water turns milky on passing carbon dioxide gas into it.
(b) Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate.
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 processes into physical or chemical
changes:
(i) Beating of aluminium metal to make aluminium foil.
(ii) Digestion of food.
(iii) Cutting of a log of wood into pieces.
(iv) Burning of crackers.
Fill in the blanks in the following statements using the wordsgiven in the box.
rusted, colourful, substance, chemical, physical,reversible, iron oxide, object
(a) Making sugar solution is a ____________ change.
(b) A physical change is generally____________.
(c) Grinding of wheat grain changes its size. It is a____________ change.
(d) Iron benches kept in lawns and gardens get____________.It is a _________ change because a new _________ is formed.
+91 94284 01196 (WhatsApp only)
C-15, Suvidhapark Society, Amitnagar circle, Karelibaug, Vadodara (390018)
© Copyright 2025. Doubtora. All Rights Reserved
