Post-Laboratory Questions (use the spaces provided for the anstoers and addition
ID: 1045844 • Letter: P
Question
Post-Laboratory Questions (use the spaces provided for the anstoers and additional paper if necesary) 1. A student was given only one graduated cylinder to use for this experiment. After using it to measure 50.0 mL of the assigned acld, the student failed to rinse or dry the cylinder before measuring out the 505 mL of the base. Would the calculated AHu be higher, lower, or the same as the literature Htn? Briefly explain this difference as a result of using only one graduated cylinder for the 2. Explain how the following changes in the procedure for this experiment would affect the results C) A glas beaker was used instead of a pressed polystyrene cup A pressed polystyrene top was used to cover the polystyrene cup after the acid and base solutions had been mixed. (2)Explanation / Answer
Solution :-
Hneutzn will be higher than the literature H neutzn in this case. The reason is that since cylinder used without rinsing contains little acid which will react with the base which is measured next and this will make base's strength lesser than the original. Now when you will do titration (neuralization) the base required will be more than the actual. and in calculation you will correspondingly get more of the H ion concentration. whearas actually the base used should be less and actual concentration of H therefore should have been less.