Answer. The common properties of chemical reactions are:
Temperature: Change in temperature will be there. This change can be increase in temperature (exothermic) or decrease in temperature (endothermic).
Formation of product: The product will be formed if the chemical reaction has taken place. Product formed can be in any state (solid, liquid or gas). This formation of product can be observed by looking out for change in color, change in odour or substance getting disappeared.
Number of products: Minimum number of products formed after chemical reaction is one. More than one number of products can be formed.