a. Reactants and products.
|The chemicals that undergo chemical changes are reactants.||The chemicals that are formed as a result of the reaction are products.|
|These are the chemicals before the reaction between them occurs.||These are the chemicals after the reaction between them occurs.|
b. Word equation and formulae equation.
|It is the representation of chemical equations by words.||It is the representation of chemical equations by symbols.|
|It is less informative.||It is more informative.|
|It is longer and non-convenient.||It is shorter and convenient.|
c. Combination reaction and decomposition reaction.
|In this reaction, different reactants are combined to form a single product.||In this reaction, a single reactant is decomposed to form multiple products.|
|It occurs either in the presence or absence of heat.||It occurs in the presence of heat only.|
d. Positive catalyst and negative catalyst.
|It increases the rate of a chemical reaction.||It decreases the rate of a chemical reaction.|
|It is used to accelerate the reaction.||It is used to slow down the reaction.|
|Mn02 is an example.||Glycerine is an example.|