[UKstudent]

Hi, I am a pharmacy student who has an exam pretty soon and I've forgotten how to use the beer lambert equation to answer the questions below. I just don't know where to start from and my core textbook only has one paragraph regarding it. So if anyone could show me how to answer the following questions below, that would be great as I know that my exam questions will be similar. Many thanks!

(b)The A(1%, 1cm) value for paracetamol in 0.1M sodium hydroxide is 715 at a wavelength of 257 nm.  Calculate the concentration in μg/ml of a solution of paracetamol in 0.1M sodium hydroxide which gives an absorbance of 0.9 in a cell of pathlength 1 mm.   
(6 marks)

(c)The concentration calculated in part (b) was as a result of a sample taken at 45 minutes from a dissolution test of a conventional release 500 mg paracetamol tablet.  The volume of the dissolution medium was 900 ml.  Calculate the amount of paracetamol (in mg) dissolved in the vessel and the percentage released from the 500 mg paracetamol tablet.
(4 marks)

[blind]

I would suggest writing out the Beer Lambert equation, then fill in what variables you can, see if you can solve for one unknown, then move on from there.