Over the counter antacid preparations relieve __________ or __________ __________. These symptoms are caused by excess stomach acid, which is mostly __________. __________ contain basic substances that either neutralize the excess acid or act in the stomach.
A __________-__________ is a process in which more acid solution is added than an antacid tablet can neutralize so that the excess acid may be titrated. This solves two major problems:
1) Back-titration 2) Some of the bases in anatacids are only partially soluble; back-titrating eliminates the problem 3) The end-point for a strong acid-base titration is sharper than with the bases in the antacids, which are intentionally weaker or slower to dissolve to be easier on the stomach.
The mass effectiveness (E) is calculated as: __________ / __________
1) E = N / W, where: N = number of moles of acid W = Mass of tablet in grams
The cost effectiveness (C) of a table is calculated as: __________ / __________
1) C = N~ / P, where: N~ = the average number of moles of acid neutralized per tablet P = The cost of one table in cents
A buret should never be run dry because..?
1) Letting all the liquid comes out runs the risk of getting an air bubble trapped in the stopcock, which can impede then proper functioning of the buret or come out in the middle of a titration throwing off data.
In this lab __________ __________ was an indicator used to inform us of if we were close to the end point.