Post-Lab Questions Would the calculated percent of BaCl_22H_20 in a sample be to
ID: 1011982 • Letter: P
Question
Post-Lab Questions Would the calculated percent of BaCl_22H_20 in a sample be too high, too low, or unaffected by the following? Briefly explain how the data ia affected and why the answer may change in each case. Soot collected on the bottom of the crumble in Step 4 but burned off in Step 7. In Step 4 the crucible and cover were still hot when you weighed them. In Step 1 the crucible and cover were not heated enough to completely remove all the moisture. Some of the barium in the original sample was as anhydrous BaCI, . rather than BaCl, >>2H, 0.Explanation / Answer
Effect on percent of BaCl2.2H2O collected by,
1. Soot collected at bottom is driven off in step 7, would have no effect or the value remiajns unaffected. As the error in weight due to soot is nullified in later step.
2. In step 4 crucible and cover were weighed when hot. This would lead to higher percent value as hot sample wouls absorb moiture and thus percent would rise.
3. If the heating is not sufficient, the remaining soot and mositure would give higher weight and thus percent value calculated would also be high.
4. If the sample was a mix of anhydrous and hydrated BaCl2, the resultant percent calculated would be lower than the actual value as the weight thus found would evenlly be distributed and overall the value would decrease.