# Addition of catalyst to reaction increases the rate because it

$\begin{array}{1 1}(a)\;\text{decrease the value of }\Delta H\\(b)\;\text{increase the value of }\Delta H\\(c)\;\text{provides on alternate reaction mechanism with a lower activation energy}\\(d)\;\text{changes the concentration of reactants}\end{array}$

Catalyst provide an alternate pathway for reaction to complete with lower activation energy without affecting enthalpy or concentration of reactants.
Hence (c) is the correct answer.
answered Dec 18, 2013