1. A systematic or determinate error effects primarily _______ while a random or indeterminate error effect primarily _______.

a) accuracy, sensitivity b) precision, sensitivity

c) sensitivity, accuracy

d) precision, accuracy e) accuracy, precision.

For questions 2-5 answer them assuming no result is rejected. An analysis of Cl resulted in the following % Cl: 3.09,3.36, 3.02, 2.99, and 3.07.

2. What is the average or mean value?

3. What is the average deviation?

4. What is the standard deviation? (You must show your detailed work.)

5. What is the relative standard deviation in ppt?

6. If any result is to be tested for rejection, which one would it be?

7. Can it be rejected for statistical reasons? (Q₉₀ for n= 5 is 0.64) Show your calculations and explain your logic.

8. The actual % Cl in this sample as determined by sending it out to a commerical analytical lab is 3.08%. What is the accuracy error in ppt.

9.  Calculate the minimum sample size  you should have  to make the overall uncertainty in the weighing be 1.5 ppt if the uncertainty in the weighing that gives a sample weight is   0.0002 g.


10.  What is the %Cl in pure BaCl₂? (If you got 17.05% for an answer you've done it wrong.)

11.  What is the net ionic reaction that occurs when AgNO₃ is added to a solution containing chloride ions? (Hint: If you have any nitrogen atoms in the reaction you've done it wrong.)

12. A small amount of solution remains in the tip of the pipet after you have let it drain 20 s. What should you do? Explain.