The rate of reaction `((dx)/(dt))` varies with nature, physical state and concentration of reactants, temperature, exposure to light and catalyst, whereas rate constant `(K)` varies with temperature and catalyst only. The rate constant `K` is given as `K=Ae^(-E_(a)//RT)` where `A` is Arrhenius parameter or pre-exponential factor and `E_(a)` is energy of activation. The minimum energy required for a reaction is called threshold energy and the additional energy required by reactant molecules to attain threshold energy level is called energy of activation.
For an endothermic reaction, which one is true if `DeltaH` is heat of reaction and `E_(a)` is energy of activation?

Options

A. (a) `E_(a) gt DeltaH`
B. (b) `E_(a) lt DeltaH`
C. (c ) `E_(a)_(lt)^(gt) DeltaH`
D. (d) `E_(a) = 0`

Answer

a

Explanation

For endothermic reaction, `E_(a) gt DeltaH`, For exothermic, `E_(a) _(gt)^(lt)DeltaH`