Question

A student obtains the following data for his experimental runs for the unknown acid

            Run 1 – 0.2541 M       Run 2 – 0.2668 M       Run 3 – 0.2549 M       Run 4 – 0.2554 M

The unknown acid is correctly known to be 0.2542 M.

-----what is the % error for the student’s data?

-----What is the % spread for the student’s runs?

Answer 1

The % error in the student’s data is
Correct score - run score/ correct score * 100
In run 1 we have
0.2542 - 0.2541/0.2542 * 100 = 0.000393391031 = 0.03933%
In run 2 we have
0.2542 - 0.2668/0.2542 * 100 = -0.00495672699 = -0.495%
In run 3 we have
0.2542 - 0.2549/0.2542 * 100 = -0.00275373721 = -0.275%
And run 4 we have
0.2542 - 0.2554/0.2542 * 100 = 0.00495672699 = 0.495

The spread are 0.2542 - 0.2541 = 0.0001 and 0.2542 - 0.2668 = -0.0126
Also 0.2542 - 0.2549 = -0.0007 and 0.2542 - 0.2554 = -0.0012