Lab -1 Worksheet

1) You did the same experiment 20 times and measured the concentration of

the product in mM. Here is your data:

9, 2, 5, 4, 12, 7, 8, 11, 9, 3, 7, 4, 12, 5, 4, 10, 9, 6, 9, 4

a) Calculate the sample standard deviation of the concentration of the

product.

b) Calculate the std percent error in your experiment, if the theoretical

product concentration should be 8mM ? 2) Two students measured the weight of 100 microliter water (density=

1g/ml) sample 5 times each. Following are the results.

Student 1

99, 100, 112, 92, 105

Student 2

72, 115,160, 68, 85

a) Calculate STD of the measurements of each student?

b) Calculate standard percent error of the measurements of the two

students. b) Which student's measurement is more accurate? Why?

c) Which Students measurement is more precise? Why?

3) i) Calculate the percent error and the standard deviation of the following

two sets of measurements obtained by three different students.

ii) Are each of these measurements precise and accurate at 5% confidence

level? Student 1

T1-82.33 g

T2105.11 g

T3-90.15 g

T4- 112.2 g

T5-75.6 g

Student 2

T1 - 62.33 g

T2-100.11 g

T3-99.15 g

T4- 98.2 g

T5 - 80.6 g

Student 3

T1 – 102.65 g

T2-102.31g

T3-78.19g

T4-85.23 g

T5 - 92.88 g

Lab -2 Worksheet

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)

1:2

ii)

1:5

iii)

1:10

iv) 1:25 6) 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?