00:01
Over here we're given a solution that is produced by 3 .75 mg per 100 ml of a certain substance a, which we know that the molecular weight of a is going to be equal to 210 g per mole, and we're told that the transmittance is equal to 39 .6%.
00:22
We are told that at a wavelength of 480 nanometers and a length cell equal to 150 centimeters, we need to calculate what is going to be the absorptivity of this compound.
00:42
So in this case, remember that this is going to follow the lambert and beer's laws.
00:46
Absorptivity is equal to the absorptivity coefficients times the path length times the concentration, usually in molarity and this is related to the transmittance as minus logarithm of t.
00:57
In this case we're going to get minus logarithm of t becomes minus logarithm of 0 .396.
01:06
It's going to give us the value for the observance which is equal to 0 .4423.
01:16
Okay so now we can directly find the value for epsilon as minus log of t divided by epsilon sorry divided by the length times the concentration we get this calculation the only thing that we require is the concentration for the substance so the concentration would be equal to in this case we have milligrams per milliliter we need to transform this into grams per liter so the transformation is direct...