Write some characteristics of the reactants and products to be expressed in the writing of chemical reaction to made more effective. Give one model of chemical equation.

Explanation

1) Chemical equations can be made more effective by expressing following characteristics of the reactants and products.
i) Physical state
ii) Heat changes (exothermic or endothermic)
iii) Gas evolved (if any)
iv) Precipitate formed (if any)
2) For example
We can change the equation `Fe_(2)O_(3)+2Al rarr 2Fe+Al_(2)O_(3)` as `Fe_(2)O_(3(s))+2Al_((s)) overset(Delta)rarr 2Fe_((s)) +Al_(2)O_(3(s))`
3) Here we inserted physical state of the substances and heating in the reaction.