In acid base titration, after complet consumption of HCl by
NaOH, addition of next drop of NaOH will give pink colour
with phenolpthalein indicator. Why this pink colour appear?
Why not blue, black, green or anything elese?

Answers were Sorted based on User's Feedback



In acid base titration, after complet consumption of HCl by NaOH, addition of next drop of NaOH wi..

Answer / sarma dvv

Phenolpthalein indicator pH range = 8.2 To 10.0.
In this pH region only Phenolpthalein indicator shows pink
colour. below this pH it was colour less.

In acid base titration, Hcl neutralisation by NaOH,after
completion of neutralisation,affition of next drop of NAOH
the pH of the solution will be above 8.2. for this reason
it was showing pink colour

Is This Answer Correct ?    31 Yes 3 No

In acid base titration, after complet consumption of HCl by NaOH, addition of next drop of NaOH wi..

Answer / arti naik

The pink colour appears due to the change in the structure
of the phenolphthalein indicator and it forms a disodium
salt due to the base NaOH which then gives it a pink colour.

Is This Answer Correct ?    7 Yes 3 No

In acid base titration, after complet consumption of HCl by NaOH, addition of next drop of NaOH wi..

Answer / umesh patel

in basic media(in NaoH), phenolphthelin shows pink color
only

colorless if pH of the media goes below 8
pink color will appear if pH goes beyond the pH of 10.00

Is This Answer Correct ?    11 Yes 8 No

Post New Answer

More Analytical Chemistry Interview Questions

why kf factor coming 0.5

5 Answers   Alkem Labs,


What is the difference between chromatographic purity and related substances?

0 Answers  


all types of questions asked at the cipla interview

0 Answers   Aurobindo, Calyx, Cipla, Graviti Pharmaceuticals,


what is the difference between system precision and method precision?

3 Answers   Teva Pharmaceuticals,


how to convert normal phase hplc to reverse phase and vice versa?

1 Answers  






in api coa contains only process impurities and in product coa contains degradation impurities?

0 Answers  


As per ICH related substances stability trend limit from initial to shelf life

0 Answers   Medley Pharmaceuticals, Micro Labs,


What is the difference between ROI & sulphates ash?

1 Answers  


if out of two set of results of moisture analysis first 1 is passing, second one is failing, is it oos ? or vice a versa first 1 is failing and second one is passing. for information mean value to be reported and in mean value the substance is ppassing, is it oos or normaal mean value to be considered?

1 Answers   JBCPL,


what is the difference between potentiometric assay and hplc assay

2 Answers   Parabolic,


how pyridine can be analysed other than GC?

1 Answers  


what is the defferance between the potency and working standard

1 Answers   Arbro Pharmaceuticals, Caplin Point, ECOlogics, Matrix, Orchid, Venus Remedies,


Categories
  • Organic Chemistry Interview Questions Organic Chemistry (342)
  • Inorganic Chemistry Interview Questions Inorganic Chemistry (123)
  • Analytical Chemistry Interview Questions Analytical Chemistry (1387)
  • Physical Chemistry Interview Questions Physical Chemistry (62)
  • General Chemistry Interview Questions General Chemistry (478)
  • Chemistry AllOther Interview Questions Chemistry AllOther (190)