During a GC analysis, n-octane (C8) and n-decane (C10) were well separated in capillary GC column (using isothermal condition at 200oC) with retention times of 5.85 min and 6.25 min, respectively, with base width of 4.0 s and 5.0 s. Unretained solvent peak occurs at 50.0 s. Calculate:

i the number of theoretical plates for n-octane (C8) and n-decane (C10).

ii. separation resolution for C8 and C10? (1 mark)

iii. if the separation is repeated using isothermal condition at 180C, predict the changes of n-decane (C10) peak retention time.