(Solved): An HPLC method was developed for the separation of the R(+) and S(-) enantiomers of Ibuprofen (Advil ...

An HPLC method was developed for the separation of the R(+) and S(-) enantiomers of Ibuprofen (Advil) a chiral non-steroidal anti-inflammatory drug.  The HPLC system was equipped with a 35 cm x 4.6 mm silica analytical column. The mobile phase consisted of a mixture of Methanol, H₂O and acetonitrile at a ratio of 50:40:10. The analysis showed 1,3,5-Tri-t-butylbenzene was un-retained in the column and eluted  in 6.5 minutes while the R(+) enantiomer and the S(-) enantiomer of Ibuprofen eluted in 11.45 minutes and 12.05 minutes respectively.  The width of the peak at the base of the R(+) and the S(-) enantiomers peaks are 36 sec and 45 sec respectively. Please calculate the following:

1.  Retention factor of the S(-) enantiomer in the analytical column. (correct answer : 0.85)
2. The relative retention (selectivity) between the two enantiomer (correct answer : 1.12)
3. The resolution (Rs) and state and state if the peaks are baseline separated. (correct answer : 0.89)
4. The number of theoretical plates for R(+) enantiomer peak (correct answer : 5827)
5. The plate height for R(+) enantiomer peak (6 x 10 ^ -5 m)

Please show work with formulas on how to get the correct answers listed.