4) Your instructor gave you a 5mM stock solution of to prepare 250ml of 0.25mM CuSO4

solution. How much of stock solution to add and how much of water to add?

5) You are given an enzyme solution to prepare a series of solutions with following

dilutions to construct a standard curve. Calculate how much of the stock solution and

how much of water to mix so that the resultant solution has the desired dilution?

i)

ii)

iv)

1:2

1:5

1:10

1:25/n6) What is the concentration of the solution prepared by mixing 2ml of 0.5M Hcl and 98ml

of water?

7) What the volume of water required to dilute 5ml of 0.45M NaOH to result a 0.15M

solution of NaOH?

8) A student used serial dilution to prepare a 1:100000 diluted solution. If the students

stock solution is 0.05M, what is the concentration of the final solution?/n11) What is the molar absorptivity coefficient of a sample of a colored compound with

concentration of 0.025M and the absorbency of 0.58?

12) What is the molar absorptivity coefficient of a sample of a colored compound measured

at 550nm wavelength with concentration of 0.03M and the absorbency of 0.88?

13) If a colored compound gave an absorbency of 0.9 and what will be the absorbency of

the sample after a 1:3 dilution?

14) A student measured the original solution in question 9 and it had an absorbency of 0.5.

The student measured its absorbency after the serial dilution described in the problem

and remeasured. What would be the absorbency? Is it a reliable measurement to

estimate its concentration if the concentration was unknown?