00:01
In this question we are given sodium bicarbonate and sodium carbonate which will act like a buffer and they are mixed.
00:10
Sodium carbonate will act like a base and sodium bicarbonate will act like an acid and we will get this equation and we are given the molarity as well as volume of both these.
00:26
Molarity of sodium bicarbonate is 0 .25 molar dissolved in 50 ml and molarity of sodium carbonate is 0 .1 molar dissolved in 150 ml.
00:42
So from here we can calculate number of moles, number of moles equal to molarity into volume, volume is in liter.
00:50
So number of moles of sodium bicarbonate will turns out to be 0 .0125 just simply multiplying this and similarly the number of moles of sodium carbonate will turns out to be 0 .015.
01:04
After mixing this the molarity will change so the new molarity will be number of moles divided by total volume, total volume will be 200.
01:16
So number of moles of sodium bicarbonate that we will get will be 0 .0625 molar.
01:24
Similarly for sodium carbonate new molarity will be number of moles that we just calculated 0 .015 divided by total volume 200 into 10 raised to power minus 3 and the new molarity or new concentration that we will get is 0 .075.
01:49
So we know the formula for pka and ph...