00:01
Hello students, in this question, that is question first, we have given ph which is equals to 12 .5 and we have given temperature which is equals to 25 degrees celsius, that is room temperature.
00:22
We have to find the concentration of oh negative ions.
00:27
To find the concentration, we know the formula that is ph plus 3 .h.
00:32
Poh is equals to 14.
00:36
So from here we can say that pohh is equals to 14 minus ph, which is equals to 14 minus ph is 12 .5.
00:47
Therefore, pohh is equals to 1 .5.
00:52
And in second formula, we have know that pohh is equals to minus log based in concentration of, oh negative ions.
01:05
So we have to find the oh negative ions.
01:08
We have poh.
01:09
So it is 1 .5 is equals to minus log base 10.
01:15
Ohh negative ions.
01:17
When the log goes to the left hand side, so it becomes concentration of oh negative ions is equals to 10 raised to power minus 1 .5.
01:28
So which is equals to, that is, which is equals to oh negative, which is equal to 1 divided 1 raised to the 10 rest to the power 1 .5, which is equal to 0 .0316 molar.
01:50
This is answer of part a, that is concentration of oh negative ion is equal to 0 .0316.
02:00
Molar.
02:03
Answer of part a.
02:06
Now same as we have to find the part b.
02:10
That is in question 2 we have given.
02:14
We have to find out the concentration of ca2 positive...