You have a solution of unknown concentration. You place this solution in your spectrometer and measure that it has an absorbance of 0.4 at 450 nm. The molar absorptivity of your product is 1500 L/moles·cm. Assuming that you are measuring the sample in a 1 cm path length cell what is the concentration of product in your solution? Report your answer in mM units.

Concentration of solution is 0.27 mM

Explanation:

We apply Lambert-Beer law to solve this problem of spectrometry:

Abs = a . L . C

where a is absorptivity, L is the length of the cuvette and C, concentration (M).

Abs is the absorbance of the solution which is readed by the spectrometer

0.4 = 1500 L/mol.cm . 1cm . C

0.4 / 1500 mol/L = C

2.67×10⁻⁴ mol/L = C

To convert the units to mM, we need to make this conversion

2.67×10⁻⁴ mol . 1000 mmoles/ 1 mol = 0.27 mM

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

the answer is 303.15 or 303