PHYSICS · Multi-part · CBSE · Physics · Units and Measurements · Units and Measurements
Problem
During a laboratory investigation, two different student groups titrate the same unknown weak acid with standardized 0.150M KOH. Each group records four trials. Their buret readings (final volume minus initial volume) are shown below.
Group 1 (mL): 24.96, 25.02, 24.98, 25.01
Group 2 (mL): 25.85, 25.89, 25.88, 25.87
(a) For each group, calculate the mean titrant volume and the standard deviation of the four trials to the correct number of significant figures.
(b) Compare the *precision* of the two data sets. Cite quantitative evidence from part (a).
(c) Only one group’s results are *accurate* relative to the true equivalence volume of 25.00mL. Identify which group and explain your reasoning.
(d) For the *inaccurate* group, identify one plausible source of systematic error that could account for the consistent deviation you observed. Describe how this error would influence the calculated molarity of the unknown acid.