Question

Which of the following statement is incorrect for a chemical reaction?

Answer 1

• The heat may be released or absorbed during a chemical change. For example, during melting of ice cubes, ice absorbs (heat) energy from the environment.
• Sound may be produced during a chemical change. For example, during bursting of crackers, sound is produced.
• A colour change may take place during a chemical change. For example, during rusting of iron, the colour of iron changes to reddish-brown colour.
• A gas may be evolved during a chemical change. For example, during burning of wood carbon dioxide is released.
• Hence, only option (a) is incorrect.