Question

If a calibration curve of absorbance vs procaine hydrochloride concentration (mol L') is linear with the equation y = 240000x for the derivatised procaine, what is the value of the molar absorptivity coefficient (Emolar)? Assume that a cuvette with a pathlength of 3 cm was used. (1 mark) Y=240000 Emolar = _ L molo

Answer 1

8000 L/ mol cm is the value of the molar absorptivity coefficient.

Step-by-step explanation:

The slope of the absorbance- concentration graph is equal to the product of path length and molar absorptivity coefficient.

`(dA)/(dc)=\epsilon l`

`(dA)/(dc)`= Rate of change of absorbance with respect to concentration

`\epsilon` = molar absorptivity coefficient

l = Path-length

Given the slope of graph of absorbance vs procaine hydrochloride concentration.

y = 240000 x (linear equation)

Path length of cuvette = 3 cm

`A=240000 c`

`A=\epsilon c* l=(\epsilon l)* c`

`240000=\epsilon * 3`

`\epsilon =(24000)/(3)=8000`

The units of
`\epsilon = 8000 l/mol cm`

8000 L/ mol cm is the value of the molar absorptivity coefficient.