Answer / bhupalreddy

*** The equation for finding the pH of a solution is –log
([H+]). That is, the negative log of the molarity of the
hydrogen ions released by the compound in solution. Almost
no chemicals can release hydrogen ions with a molarity
greater than 1 or less than 10^-14. However, there are some
rare cases where the pH of a solution is not between 0 and
14. For example, 10 molarity hydrochloric acid (there are
ten moles of hydrochloric acid for every liter of water.),
has a pH of -1 (-log (10) =-1). But these are so rare in
occurrence

Answer / spatil

No one can gives satisfied answer....

Answer / sp goswami

The pH concept was introduced in 1909 by the Danish chemist
S.P.L.Sorenson

pH is defined by the negative logarithm of the hydrogen ion
activity:



where aH = activity of the hydrogen ion

The pH scale derives from the characteristics of the auto-
dissociation of Water. Pure water has a low conductivity
and is only slightly ionised however does Water dissociate
slightly into Hydronium ions and hydroxide ions:

or

The concentration of H+ and OH- ions, which are equal, are
1x 10-7 ions per litre The equilibrium constant (or ion
product ) for the dissociation of water, Kw, is



by taking logs of both side we get:



Using the standard abbreviation p for {-log10} we get:



This equation sets the pH scale to 0-14, which gives a
convenient way to express 14 orders of magnitude of [H+].
Any solution with pH>7 contains excess hydroxyl ions and is
alkaline those with pH<7 are acidic, containing excess
hydrogen ions. Regards

Answer / panchanan basantia

 pH stands for potency of hydrogen or strenght of hydrogen

the con. of hydrogen is 10nth to the power -14 so pH value is shows 1 to 14

Answer / usharani

Because of condivity of water is 1.0 x 10 -14
if water dissociation is H+ and OH-

H2O = 1.0 x 10-14
log (H2O) = log (1.0 x 10-14)
PH = 14.

Answer / a. lavanya

it is basic nature so pH IS 0-14

IN DISSOLUTION WE ARE USING A LETTER 'Q' WHAT IS MENT BY Q

5 Answers   Reddy Labs, Torrent Pharma,

for inorganic molecules require to do RS, Assay and disso?

0 Answers  

in DMF having extra impurities and in api COA also having extra imp than USP or BP product then how require to proceed?

0 Answers  

When we calculate Impurity against impurity std.solution and when we calculate impurity against diluted standard with applying RRF?

2 Answers   Torrent Pharma,

we can use expired sample for validation and analyst qualification?

0 Answers  

If vendor having more imp than monograph then how to proceed? and how to set spec?

0 Answers  

what is mean by 40 in the dissolution basket mesh size?

0 Answers  

Which are the diffrent grades of api in pharma?

0 Answers  

Why sulfuric acid is used in sulphated ash / residue on ignition test.

9 Answers   CS Pharmaceuticals, Dr Reddys, GVK, HPLC, Micro Labs, Samrudh, Watson Pharmaceuticals, Wings Customer Care,

what is end capping in hplc coulmn

2 Answers   Lupin, Zydus Cadila,

why kf factor coming 0.5

5 Answers   Alkem Labs,

How we will choose pH of a mobile phase if analyte pKa value is 4

2 Answers   Celon Labs, Laurus,