00:01
This question asks you to determine each quantity, but i only see one quantity.
00:06
They want the ph at 10 .7 milliliters of added base.
00:11
The reaction is going to be one -to -one, where one mole of potassium hydroxide reacts with one mole of hydrobromic acid to produce potassium bromide and water.
00:26
So, to determine the ph, we first need to figure out what is going to be in excess.
00:33
We're starting with 32 milliliters of 0 .175 molar of hbr, and then we're adding just 10 .7 milliliters of 0 .205 molar koh.
00:48
So, we're not adding enough koh to react with all of the hbr, so we're going to have excess hbr.
00:55
To calculate the excess hbr concentration, we'll start with the moles of hbr.
01:01
That's 32 milliliters, or 0 .0320 liters, at a concentration of 0 .175 moles per liter.
01:13
This is the moles of hbr we start with, the volume times the molarity.
01:18
We then subtract off the moles that react...