UPSC Combined Geo-Scientist, Mains · 2021 · Mains Paper I
Q7(b). Practical conditions in iodine and permanganate titrations
Question
Give reasons for the following: (i) Starch solution is added near the end point in iodometry titrations. (ii) Why is hot solution titrated against KMnO₄ solution? (iii) Potassium iodide is added in iodometric titration.
Model answer
The free solution for 2021 answers questions 1, 2, 5, 6, 9 and 11, the ones picked in its time plan. Question 7 is answered in full in the Geo-Scientist Chemistry Paper I, 2021 to 2025 book, with every part of every paper.
Part of VKC Basic
Read the key points and the full model answer with VKC Basic
VKC Basic (₹999 for 6 months) opens every solved answer, the notes, the handbook and the daily answer archive. Every Mains test series includes it.
Printed copy and Kindle
UPSC Combined Geo-Scientist (Main) Chemistry Paper I: Model Answers 2021 to 2025
- All eleven questions of each paper, with the question printed above its answer
- Titration, gravimetric and nuclear numericals worked with units; structures drawn
- Topic-wise weightage and a topic-wise index
Coversiodometrystarch indicatorKMnO4 titrationoxalic acidpotassium iodidetriiodide
All parts of Question 7
- 7(a) Types of redox titration15 marks
- 7(b) Practical conditions in iodine and permanganate titrations15 marks