Question

You are responsible for making the CuSO₄ solution for the lab. If the final concentration should be 100 mM CuSO₄, how will you make the solution? You added 3 MICROLITERS of the 100 mM CuSO4 solution to your cells containing 3 ml of DMEM. What is the final concentration of CuSO₄ in your wells?

Answer 1

molecular weight of CuSO4 = 159.609 g/mol this means 159.609 g if CuSO4 in 1 litre of water gives 1000 mM or 1M of CuSO4

we need 100 mM of CuSO4 ,for this weight 15.96 g of CuSO4 and dissolve in 1 litre of water which gives 100 mM of CuSO4

when we added 3 ul of the 100 mM CuSO4 solution toyour cells containing 3 mL of DMEM the 100 mM CuSO4 is getting double diluted (3 + 3 = 6ul) hence its molarity becomes 50 mM

hence the final concentration of CuSO4 in your wells is 50mM.