00:01
Hello everyone in this question they have asked that what is the ph of solution containing ephedrine about 0 .1 molar and ephedrine hcl solution about 0 .01 molar concentration.
00:13
Here they have given kb for ephedrine that is 2 .3 into 10 raised to minus 5.
00:19
So first we are going to write the balance to chemical reaction here that is c10 h15 no in presence of water here this one here what happen here h2o it donate h plus ion to c10 h15 no here it produce c10 h15 no h plus no dot h plus plus oh minus.
00:57
So after that we are going to write kb expression for this.
01:00
So kb is equal to concentration of c10 h15 no h plus into concentration of oh minus upon concentration of c10 h15 no.
01:22
So here they have given the concentration of c10 h15 no that is 0 .1 molar and also here they said that ephedrine hcl solution they have given that is the concentration of ephedrine hcl is concentration of ephedrine hcl is how much it is that is 0 .01 molar here the total concentration become 0 .01 into 0 .1 becomes 0 .11 molar.
02:03
So at equilibrium what happens kb is equal to here at equilibrium the concentration of c10 h15 no dot h plus is x and oh minus concentration is also x upon here it is 0 .11 minus x.
02:20
So here we are going to find out x value for that they have given kb value which is equal to 2 .3 into 10 raise to minus 5 is equal to x square upon 0 .11 minus x.
02:36
So here if we solve x we will get x value which is equal to 0 .0011 molar.
02:45
So this is equal to the concentration of oh minus and concentration of concentration of oh minus and concentration of c10 h15 no dot h plus.
03:06
So this is the 0 .0011 molar concentration which is equal to oh minus concentration and c10 h15 no dot h plus concentration.
03:20
So here we got the concentration of oh minus that is 0 .0011 molar after that we are going to find out ph of solution...