Question

Name the various characteristics which indicate that a chemical reaction is taking place.

Answer 1

1. Chemical reaction: When one or more substances (called reactants) are converted into different substances (called products), then this change is referred to as a chemical reaction.
2. Example-

$$\begin{gathered} \mathrm{Zn}\left(\mathrm{s}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{ZnSO}}_4\left(\mathrm{aq}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)\uparrow \\ \mathrm{Zinc}\mathrm{Sulphuric}\mathrm{Zinc}\mathrm{sulphate}\mathrm{Hydrogen} \\ \mathrm{acid} \end{gathered}$$

3. Characteristics that indicate a chemical reaction:

• Evolution of a gas.
• Change of color.
• Formation of a precipitate.
• Energy change.
• Change of physical state.