Question

CRITICAL THINKING.

Kindly show your solution.
Experiment 1 21.500 ml
Experiment 2 21.501 ml
Experiment 3 21.498 ml
Experiment 4 22.000 ml
Experiment 5 21.599 ml
Standard is 22 ml
a. Get the uncertainty
b. Get the error through the mean
c. Percentage error
d. Which is it closer to the accuracy?
e. Is the experiment precise or accurate? Why (7 sentences)​

Answer 1

The experiment demonstrates precision in the consistent closeness of the measurements to each other but lacks accuracy since they are not as close to the standard value of 22 ml.

Step-by-step explanation:

The question involves calculating the uncertainty, mean error, percentage error, and assessing the accuracy and precision of volumetric measurements in a scientific experiment. These concepts are fundamental in Chemistry, as they pertain to the reliability and validity of experimental results.

Firstly, uncertainty is the measure of the range within which the true value can lie, based on the precision of the measurement instrument. To calculate this, you would consider the least count of the measuring device or the range of values obtained. In the case of Experiment 1 to 5, the measurements are all close to each other with minor differences, indicating a low uncertainty.

The mean error is the difference between the average of the measured values and the accepted standard value. It is a measure of accuracy, where you compare the experimental mean to the standard 22 ml. To find this, sum all measured values, divide by the number of measurements to find the mean, and subtract the standard value from this mean.

Percentage error is the mean error expressed as a percentage of the standard value. This helps in understanding the error in the context of the measurement scale. You calculate it by dividing the mean error by the standard value and then multiplying by 100.

For the final question regarding accuracy and precision, we can compare the results to the definitions. If the results are close to the standard value, they are accurate. If the results are close to each other, the measurements are precise. Examining the given measurements, they are overall more precise than accurate since they are consistently close to each other but not as close to the standard of 22 ml.

In conclusion, while the experiment shows precision, it lacks accuracy since the measurements are consistent with each other but not with the standard value.