Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 11-science Answered

what is the value of concentration of [h3o] and  [oh] in neutral aqueous solution a 298k?ste their ph and poh value
Asked by Prakash | 28 Jun, 2018, 06:09: PM
answered-by-expert Expert Answer
Water undergoes self-ionisation to a small extent as,
 2 straight H subscript 2 straight O space space rightwards harpoon over leftwards harpoon with blank on top space straight H subscript 3 straight O to the power of plus space space plus space space OH to the power of minus

straight K subscript straight w space equals space left square bracket straight H subscript 3 straight O to the power of plus right square bracket space left square bracket OH to the power of minus right square bracket
 
The constant Kw is called as an ionic product of water.
Its value at 298K is 1.008 X 10-14 Mol2 L-2.
I n space p u r e space w a t e r space left square bracket H subscript 3 O to the power of plus right square bracket space a n d space left square bracket O H to the power of minus right square bracket space a r e space e q u a l.
space space space space space space space space space space space K subscript w space equals space space left square bracket H subscript 3 O to the power of plus right square bracket space space left square bracket O H to the power of minus right square bracket
o r space space space space space space space space K subscript w space equals space space left square bracket H subscript 3 O to the power of plus right square bracket squared space space space space space space space space space space space space space space space space space because space space left square bracket H subscript 3 O to the power of plus right square bracket space equals space space left square bracket O H to the power of minus right square bracket

space space space space space space space therefore space space left square bracket H subscript 3 O to the power of plus right square bracket space equals space square root of K subscript w end root

A t space 298 K comma space left square bracket H subscript 3 O to the power of plus right square bracket space equals space square root of 1.008 space cross times 10 to the power of negative 14 end exponent end root
space space space space space space space space space space space space space space space space space space space space space space space space space space space equals space 1 space cross times space 10 to the power of negative 7 end exponent space m o l space L to the power of negative 1 end exponent

H e n c e comma space space left square bracket H subscript 3 O to the power of plus right square bracket space equals space space left square bracket O H to the power of minus right square bracket space equals space 1 space cross times space 10 to the power of negative 7 end exponent space m o l space L to the power of negative 1 end exponent
 
 
Now, let's find the pH and pOH value,
 
pH = log[H+]
     = log [1 X 10-7]
pH = 7
 
 
 pH + pOH = 14
  7 + pOH  = 14
         pOH = 7

Answered by Ramandeep | 29 Jun, 2018, 11:25: AM
CBSE 11-science - Chemistry
Asked by achamerahul2 | 21 Apr, 2020, 02:33: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Chemistry
Asked by achamerahul2 | 21 Apr, 2020, 02:32: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Chemistry
Asked by mufeedatvp2000 | 18 Apr, 2020, 02:21: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Chemistry
Asked by Prakash | 28 Jun, 2018, 06:09: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Chemistry
Asked by gganga | 10 Apr, 2018, 06:31: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Chemistry
Asked by Topperlearning User | 04 May, 2015, 03:13: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Chemistry
Asked by Topperlearning User | 30 Apr, 2015, 02:30: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Chemistry
Asked by Topperlearning User | 16 Jun, 2016, 05:24: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
Get Latest Study Material for Academic year 24-25 Click here
×