00:01
Question number one wants us to identify which of the following statements is our true regarding color indicators.
00:09
I assume they mean indicators for titrations.
00:13
The first statement says a color indicator is most effective over a large range.
00:19
This is typically false as the indicator transition range is only plus or minus 1 p .8.
00:34
Unit from p .a.
00:36
So the range is pretty much always just two ph units.
00:41
So this would be false.
00:43
A large range would be false.
00:47
The second statement says color indicators are typically weak acids or weak bases themselves.
00:53
This is true.
00:55
It is the protonated form that is of one color and the deprotonated form that is of a different color.
01:06
Statement c, color indicators are used in titrations to signal the completion of an acid -based reaction.
01:15
Yeah, this is typically the most prominent use of a color indicator.
01:22
It'll change color at the ph range of the equivalence point.
01:29
And then the last one, titrations of polyprotic acids may require the use of more than one color indicator.
01:36
So this is true if we want to see all of the equivalence points.
01:47
So because statement a was false, color indicators are effective over a large range, meaning they're only effective over a small range, we may need one indicator for this color change, this transition, this equivalence point, and another one here, and another one here.
02:07
So oftentimes more than one indicator is used.
02:12
This is true.
02:15
So it looks like all of them are true except the first one.
02:20
Now for question two...