Answer / b.gangatharan

According to Quinonoid theory acid base indicators exist in two tautomeric forms having different structures. phenolphthalein has benzenoid form in acidic medium and thus it is colourless while it has quinonoid form in alkaline medium which has pink colour.

Thanks,
B.Gangatharan.
Caplin Point.

difference between AAS & flame photo meter ?

3 Answers  

---

what are the primary standards of redox titrations?Name any two.

2 Answers   Laurus,

---

What is difference b/w IR&NIR

1 Answers   Apotex,

---

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 limit of Correlation for IR test compare to the standard and test

3 Answers   Nakoda Chemicals,

---

---

How we can identify process related and degradation impurity in single method with short period?

0 Answers  

---

why we are using 6 dosage units in dissolution, and why we are using 6 tablets in disintegation test.is there any scientific reason beyond 6?

1 Answers   ABC, Alembic, IPCA,

---

How we choose the mobile phase for method development.?

0 Answers  

---

in loss on drying Why follows on constant weight not more than 0.5 mg, any region

1 Answers   Biocon,

---

what is least count of a balance? How we find out this? Any formula for least count of Analytical balance?

13 Answers   Acme Formulation, Analytical Solutions, Dr Reddys, Reddy Labs,

---

Why irmoisture balance is used for corrugated box moisture testing

0 Answers   Leiutis, Lupin,

---

What does theoretical plates number mean?

1 Answers   Zydus Cadila,

---