Question

List one observation that determine a chemical reaction has taken place along with corresponding balanced chemical equation for the justification of observation ?

Answer 1

(a) Three observations that determine that a chemical reaction has taken place are :  (i) Change in state and colour  (ii) Evolution of gas  (iii) Change in temperature. Three informations that cannot be obtained about a chemical reaction, merely by its chemical equation are :  (i) The state of a matter of the reactants and products.  (ii) Amount of heat evolved or absorbed in a reaction.  (iii) The change of colour after the chemical reaction. (b) Balance chemical equations : (i) 3Fe + 4H2O → Fe3O4 + 4H2 (ii) 6CO2 + 6H2O → C6H12O6 + 6O2