- Joined
- May 23, 2014
- Messages
- 265
- Reaction score
- 37
Two questions:
In a buffer, if plotted on titration graph, it'd be a straight line with pH = pKa?
Also, for this problem(#9), why do u need to have an indicator pKa less than 7? Since this is a weak base, NH3 diluted by strong acid HCl, then the pH at equivalence is less than 7.
So for indicator active range, it should be plus or minus the pH at the equivalence point. Thus, since a pH lower than 7 would be 6, the indicator can only have a pKa of 5-7? Hence H-IndK (pka 7.43) is too great and not the correct answer? Can someone verify my thinking on this? Thanks
In a buffer, if plotted on titration graph, it'd be a straight line with pH = pKa?
Also, for this problem(#9), why do u need to have an indicator pKa less than 7? Since this is a weak base, NH3 diluted by strong acid HCl, then the pH at equivalence is less than 7.
So for indicator active range, it should be plus or minus the pH at the equivalence point. Thus, since a pH lower than 7 would be 6, the indicator can only have a pKa of 5-7? Hence H-IndK (pka 7.43) is too great and not the correct answer? Can someone verify my thinking on this? Thanks