CHEMISTRY · Multi-part · CBSE · Chemistry · Acids, Bases and Salts · Acids, Bases and Salts
Problem
In a dehydration experiment, a student heats 3.21 g of blue copper(II) sulfate pentahydrate (CuSO₄·5H₂O) in a crucible until a constant mass of the white anhydrous solid (CuSO₄) is obtained. The crucible and contents are allowed to cool and are weighed at 2.05 g. Atomic masses (g mol⁻¹): Cu = 63.55, S = 32.07, O = 16.00, H = 1.008.
(a) Calculate the experimental mass percent of water lost during heating.
(b) Determine the theoretical mass percent of water in CuSO₄·5H₂O based on atomic masses.
(c) Calculate the percent error between the experimental value in part (a) and the theoretical value in part (b).
(d) Propose one plausible experimental source of error that could account for the difference between the experimental and theoretical percentages, and explain its effect on the calculated mass percent of water.