00:01
Okay, hope i can do this one.
00:02
We are asked to calculate ph when 100 .0 milliliters of 1 .0 molar hcl, which will be 0 .100 liters times 1 moles per liter equals 0 .100 moles of hcl, are added to 500 milliliters of a buffer solution that is 0 .500 molar hf and 0 .500 molar naf.
00:50
So that will, if i take that moles per liter, moles per liter times 0 .500 liters, that will be 0 .250 moles.
01:09
Let me do that math quick.
01:10
0 .250 moles of each.
01:16
Okay, so we're going to use the henderson -hasselbalch equation to do this.
01:26
My new volume will be 600 milliliters and i'm going to go 500 milliliters plus 100 milliliters.
01:45
Let's see here.
01:49
And i have an initial concentration or initial moles of, i'm going to add hcl, which is h plus, and that will combine with my f and that will give me my h.
02:14
So my original concentrations of f are 0 .250 and 0 .100.
02:34
So my change will be negative 0 .100, negative 0 .100, and plus 0 .100...