Chapter 9.6, Problem 2QQ

Interpretation Introduction

Interpretation:

From the given options, one which decrease the rate of the given reaction has to be chosen.

    ${\text{S}}_{\text{(S)}}{\text{+O}}_{\text{2(g)}}\to {\text{SO}}_{\text{2(g)}}$

Concept Introduction:

Rate of a Chemical Reaction:

It is the rate of change of concentration of reactant or product per unit time or it is expressed in by decrease in concentration of reactant or increase in concentration of product.

Factors affecting the rate of a chemical reaction:

1. 1. Concentration of Reactants:

Rate of the reaction is directly proportional to concentration of the reactants.

    ${\text{r=kc}}^{\text{n}}$

    c = concentration

    n = order of the reaction

    k = specific rate

1. 2. Reaction Temperature:

Increase in temperature will increase the average kinetic energy of the reactant molecules.  It is very easy for the molecules to move and thus makes the collision more effective.  A large fraction of collisions will result in the product

1. 3. Presence of Catalysts:

   Catalyst is a substance which can increase the rate of the reaction without altering the reaction.  It will provide an alternative pathways for the reaction, thereby lowering the activation energy.  For attaining equilibrium in a reversible process, the catalyst will lowers the activation energies of both forward and backward reactions.