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  CSIR NET Chemical Sciences 2024–2025 PYQs with Detailed Solutions (Part 2) Practicing Previous Year Questions (PYQs) is one of the most effective ways to crack the CSIR NET Chemical Sciences examination. In this article, we continue our PYQ series with another set of important concept-based questions from Physical, Organic, and Inorganic Chemistry. Question 1 Which of the following species is isoelectronic with Ne? (CSIR NET Chemical Sciences – June 2025) பின்வரும் துகள்களில் எது Ne உடன் isoelectronic ஆகும்? A) Na⁺ B) Mg²⁺ C) F⁻ D) All of the above Answer: D) All of the above Solution: Neon has 10 electrons. Na⁺ (11−1=10), Mg²⁺ (12−2=10), and F⁻ (9+1=10) all contain 10 electrons. Hence all are isoelectronic with Ne. Question 2 The hybridization of carbon in CO₂ is: (CSIR NET Chemical Sciences – December 2024) CO₂ இல் கார்பனின் hybridization என்ன? A) sp B) sp² C) sp³ D) dsp² Answer: A) sp Solution: Carbon forms two double bonds with oxygen atoms. Therefore, there are two elect...

h1 style="text-align: center;"> CSIR NET Chemical Sciences 2024–2025 PYQs with Detailed Solutions (Part 2) The magnetic moment (spin-only) of a d³ ion is: (CSIR NET Chemical Sciences – June 2024) d³ அயனின் spin-only காந்தத் திருப்புத்திறன் (magnetic moment) என்ன? A) 1.73 BM B) 2.83 BM C) 3.87 BM D) 4.90 BM Answer: ✅ C) 3.87 BM Detailed Solution: For a d³ ion, the number of unpaired electrons (n) is 3. Spin-only magnetic moment is given by μ = √[n(n+2)] BM. Therefore, μ = √[3(3+2)] = √15 = 3.87 BM. Hence, the correct answer is C. Which of the following has the highest electronegativity? (CSIR NET Chemical Sciences – December 2024) பின்வருவனவற்றில் அதிக மின்எதிர்மறைத்தன்மை (electronegativity) உடையது எது? A) Oxygen B) Nitrogen C) Fluorine D) Chlorine Answer: ✅ C) Fluorine Detailed Solution: Electronegativity increases across a period and decreases down a group. Fluorine is the most electronegative element in the periodic table with a Pauling value of 3.98. Therefore, fluo...

  CSIR NET Chemical Sciences 2024–2025 PYQs with Detailed Solutions | Most Expected Questions for Exam Preparation Are you preparing for the CSIR NET Chemical Sciences examination? One of the smartest preparation strategies is practicing Previous Year Questions (PYQs). PYQs help you understand the exam pattern, identify important topics, and improve your problem-solving speed. In this article, we have compiled easy and concept-based CSIR NET Chemical Sciences questions from recent examinations along with detailed solutions. These questions cover Physical Chemistry, Inorganic Chemistry, and Organic Chemistry fundamentals that are frequently tested in the examination. Why Should You Practice CSIR NET PYQs? ✔ Understand the latest exam pattern ✔ Identify frequently asked topics ✔ Improve conceptual clarity ✔ Enhance time management skills ✔ Boost confidence before the examination Important Topics Covered Atomic Structure Chemical Bonding Coordination Chemistry Thermodynamics Chemical ...