The reactions:

(i) $2\mathrm{NO}+{\mathrm{O}}_2\to 2{\mathrm{NO}}_2$ 

(ii) $2\mathrm{CO}+{\mathrm{O}}_2\to 2{\mathrm{CO}}_2$ 

Look to be identical, yet the first is faster than the second. The reason is that:

The first reaction has higher activation energy than the second

 The first reaction has lower enthalpy change than the second
 

The first reaction has lowe internal energy change than the second
 

The first reaction has lower activation energy than the second