Question

A solute with a retention time of 407 s has a width at the base of 13.0s on a column 12.2 m long. Find the number of plates and plate height.

Answer 1

Answer : The number of plates and plate height is, $1.57\times 10^4$ plates and $7.77\times 10^{-4}m$ respectively.

Explanation : Given,

Retention time = 407 s

Width of a base = 13.0 s

Length = 12.2 m

First we have to calculate the number of plates.

Formula used :

$N=16\times (\frac{t_r}{w})^2$

where,

N = number of plates

$t_r$ = retention time

w = width of a base

Now put all the given values in the above formula, we get:

$N=16\times (\frac{407}{13.0})^2$

$N=1.57\times 10^4$ plates

Now we have to calculate the plate height.

Formula used :

$H=\frac{L}{N}$

where,

H = height of plate

L = length

N = number of plates

Now put all the given values in the above formula, we get:

$H=\frac{12.2}{1.57\times 10^4}$

$H=7.77\times 10^{-4}m$

Thus, the number of plates and plate height is, $1.57\times 10^4$ plates and $7.77\times 10^{-4}m$ respectively.