Draw Lewis structures for these ions and show which atom in each bears the for-mal

1. An open tubular gas chromatography column is 35.7 m long and has an inner diameter of 0.250 mm. It is coated on the inside wall with a layer of stationary phase that is 1.8 µm (0.0018 mm) thick. Unretained solute, methane, passes through in 6.39 min, whereas toluene has a retention time of 16.35 min. 2. Listed in the table of chromatographic data below are the retention times and peak widths for a chromatographic separation carried out on a 10.0 cm column. Calculate the plate height, in millimeters, for pyrene. Compound Time (min) Width 1/2n) Unretained 0.90 ­ Benzene 10.90 0.400 Benzo[e]pyrene 13.30 0.400 Pyrene 16.70 0.450 Coronene 26.10 0.500 3 3. Two species, A and B, are separated on a 2.00 m long column which has 5.000 x 10 plates when the flow rate is 15.0 mL/min. A species that is non­absorbing and known not