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40,000 should be split as 4 multiplied by 10 to power 4.
this is 4 and log 4 can be seen as 2log2,what is that ?4.602,so i have to move downward
by 4.6 unit ,from 6 i will be about 1.4,
1.380 is the correct ans.
how many people understood this?
have you really understood what is the meaning of this came,we can manipulate them.
ok,tell me ,you are at PH=4,and you are diluting 100 times ,where you will stand?
yes,6,very good because PH=4 has a drop that has good number of particles ,when we are diluting it 100 times ,10 times the particle will reduce ,10 by 10 ,in log you will move by 1 unit,
then again you shifted,you diluted it one more 10 times ,10*10*=100 times,so the particles which are left here are effectively very low.
you have to move on log. scale by 2 units.
so you will from 4 to 6,so whenever you are diluting ,you will go in this direction ,diluting means per drop will have smaller value ,so the width will decrease ,concentrating means per drop will have more number of particle.so width will decrease.
like wise for the basic solution you can tell
now let me go to that slide,
ionic product of water,
what does this indicate?
Pkw is decreasing ,means the range at which you were working earlier ,please look i will explain you here itself,
at 25 degree celcius,i was working with range of 14 ,here to here,
and the mid point utility point exact 7 ,this was 14 this was 0,
this is true ,when you are at 25 ,somewhere ,13.99 is 14,this is some scientific value ,for practical you will use is 14.
now think at 50 degree celcius,it is 13.2,that means this range is reduced from 14 to ,it is shrunk into smaller range only
where it is not as large ,it is smaller one,and its middle point ,obviously 14's half was 7 ,13.2's half should 6.6,
that is the neutrality point ,ok and below this 0 above this 13.2,
let me speak that at 100 degree celcius,say this was about 50 degree ok,say 100 degree celcius,this value range moves to 12.
what should i do then?it is 100,there i will write here 12. tell me?
if it 100 and 12 ,i will write a range
which is further shrunk only on 12 units ,whose mid point is 6
and its highest value is 12,least value is 0.
ok, where i wanted to stress ?i wanted to stress here.that neutrality point
its not dependent on PH.
if some one blindly say that if PH =7,and solution is neutral.
he may not be correct always.
if at 25 degree celcius,it is correct.neutrality is not decided by PH. neutrality is decided by the balance of H and OH ions,
and balance of H and OH ions ,it depends on the dissociation that how many H and OH ions are produced,it depends on the temperature and dissociation,so as the temperature increases
you find that dissociation increases therefore the range started to shrink and the mid point of the range changes.
now i will ask one question you tell me ?
at 100 degree celcius ,if 6.5
PH is observed,what is the nature of solution ?acidic or basic?
basic,well, very good.why?
100 degree celcius ,6 is the neutral point therefore 6.5 point should come in the basic range.
and solution will basic and at 25 degree celcius if it is 6.5,it is acidic to PH 6.5 it doesn't decide any thing.
until it is mention with the temperature .
i think now you understood why we require ionic product .because i have a PH meter ,i took the PH meter i dip this prob into the solution,and found the reading,reading is 6.3,
i am jumping that solution is acidic,
and when to teacher he said no its basic.
so where did i go wrong ?
i was not aware about the temperature.