Astudent researcher performed a chromatographic separation of caffeine and aspartame. the retention time for caffeine, t c , was found to be 216.7 s with a baseline peak width, w c , of 13.6 s. the retention time for aspartame, t a , was 267.1 s with a baseline peak width, w a , of 18.9 s. the retention time for the unretained solvent methanol was 45.2 s.

calculate the average plate height, h , in micrometers for this separation, given that it was performed on a 24.1 cm long column.
h = μ m

calculate the resolution, r , for this separation using the widths of the peaks.
r =

calculate the resolution if the number of theoretical plates were to increase by a factor of 1.5 .
r 1.5 n =

Average plate height: 67,4μm

Resolution: 3,10

Resolutin with increase N by a factor of 1,5: 3,80

Explanation:

Average plate height is the average between plate height of aspartame and caffeine.

Plate height is:

For aspartame:

H = 75,4 μm

For caffeine:

H = 59,33 μm

Average plate height is:

(59,3μm + 75.4μm)/2= 67,4μm

The resolution formula is:

Replacing:

R = 3,10

As resolution is proportional to the square root of the number of theoretical plates, the increasing of 1,5 in the number of theoretical plates increases the resolution by a factor of √1,5 ≈ 1,22

That means resolution would be:

R 1,5N = 3,10×√1,5= 3,80

I hope it helps!

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

> b takes place in the gas phase in an isothermal tubular reactor. the feed is one mole of a per one mole of c, an inert. the entering temperature and pressure are 427°c and 10 atm, respectively. the gas constant r = 0.08206 atm · l/mol · k.