Question

How to find order of a reaction if k is given?

Answer 1

 The common patterns used to identify the reaction order are described in this ..... a first-order reaction should give a straight line with a slope of −k and 

Answer 2

Unit of k = $(mol \: \times \: litre^{ - 1} )^{n - 1} {s}^{ - 1}$
Where n = order of the reaction.
Compare with the unit of k given by equating both the units, and accordingly find the order from this equation.