00:01
So in this case, instead of having a typical weak acid congey base system, we have a weak base congey acid system.
00:06
So we can apply the analog of the henderson -hauselbach equation, which is the p -o -h equals the piquet b, plus the log concentrations of our congey acid and weak base.
00:17
So already given information that the concentration of base initially is 0 .5 .00 moles, molar.
00:25
And we're going to add a 0 .125 moles of ammonium chloride to our so we're given that the volume is equivalent to 0 .5 .00 liters.
00:37
So in this case, we're going to assume that adding our conjugate acid isn't going to change the ph, isn't going to change the volume of solution.
00:45
And we're going to assume in this case that our essentially the conjugate acid is not going to initially react.
00:53
And we need to convert our conjugate acid in terms of concentration due to the requirements of the equation.
00:59
So we can find that the concentration of our conjugate acid is 0 .250 molars.
01:07
Now we can substitute everything into our henderson -hosselbach equation with the knowledge that the p .kb is 4 .74, which can be found from a table.
01:18
And by substituting everything into our equation here, we can find that the p .o .h as a result of this is 4 .44.
01:26
And we know that 14 minus the p .o .h is equivalent to the ph.
01:29
So we can find that the ph is initially 9 .56.
01:33
So now we're going to stress the system by adding essentially hcl, our strong acid.
01:42
So we can see that the only compound in our system that can react to resist the strong acid is our weak base in this case, since our strong acid reacts with our base to form more of our conjugate acid...