in mitochondria the inner memberane is impermeable.then how will the cell pass the components inside and outside the cell?

The outer membrane contains many copies of a transport protein called porin, which forms large 

 aqueous channels through the lipid bilayer. This membrane thus resembles a sieve that is permeable to all molecules of 5000 daltons or less, including small proteins. Such molecules can enter the intermembrane spaces, but most of them cannot  pass  the impermeable inner membrane. Thus, whereas the intermembrane space is chemically equivalent to the sytosol with respect to the small molecules it contains, the matrix contains a highly selected set of these molecules.