A feasible error could have been the removal of the sample before all water evaporated.
Explanation:
In order to determine the percentage of water in an hydrate, an experiment that could be performed is the heating of the sample until the mass does not change. If the student heated the sample an insufficient amount of time, water will be present in the sample, thus reducing the percentage reported.
converts to in the first reaction. The coefficient in front of is three times the coefficient in front of . In other words, each mole of will produce three moles of . 0.0020 moles of will convert to 0.0060 moles of .
How many moles of thiosulfate ions are required?
reacts with in the second reaction. The coefficient in front of is twice the coefficient in front of . How many moles of does each mole of consume? Two. 0.0060 moles of will be produced. As a result, moles of will be needed.