Question

" A teacher instructs her students to measure out 50.0 mL of hydrogen

peroxide for three trials of an experiment. A student measures out 37.2 ml,
38.7 mL, and 36.9 mL.
Use this information to answer the questions below (1a and 1b).
1a. Calculate the percent error for each measurement and include them below. (For example: 1%, 2%, 3%) *
Your answer
1b. Using the percent errors that you calculated in the first part, discuss if these measurements are accurate, precise, both, or neither. Explain why."

Answer 1

The percent errors for the given measurements are -25.6%, -22.6%, and -26.2%. These measurements are neither accurate nor precise because they deviate significantly from the target value and vary by more than a few tenths of a milliliter from each other.

Step-by-step explanation:

The percent error can be calculated by using the formula:

Percent error = (|experimental value - accepted value| ÷ accepted value) x 100%

Let's calculate the percent error for each measurement:

Percent error for the first measurement: ((37.2 - 50.0) ÷ 50.0) x 100% = -25.6%

Percent error for the second measurement: ((38.7 - 50.0) ÷ 50.0) x 100% = -22.6%

Percent error for the third measurement: ((36.9 - 50.0) ÷ 50.0) x 100% = -26.2%

Based on the calculated percent errors, we can conclude that these measurements are neither accurate nor precise. Accuracy refers to how close the measured values are to the target value, while precision refers to how close multiple measurements are to each other. In this case, the measurements are not accurate because they are all more than 10 mL too low compared to the target value of 50.0 mL. Additionally, the measurements are not precise because they vary by more than a few tenths of a milliliter from each other.