Question

Which movement is required for the IR spectroscopy?

• A. Dipole movement
• B. Spin movement
• C. Round movement
• D. All of the above

Answer 1

The Correct Option is A

Step 1: Understanding Infrared (IR) Spectroscopy. - Infrared spectroscopy is used to study molecular vibrations by detecting changes in dipole moment. - IR radiation excites vibrational modes like stretching and bending, causing variations in molecular dipole moment. 

Step 2: Explanation of molecular movement. - Dipole movement: Required for IR activity since molecules must undergo a change in dipole moment when vibrating. - Spin movement: Relevant in NMR spectroscopy, not IR spectroscopy. - Round movement: Not a recognized molecular motion in spectroscopy. 

Step 3: Explanation of incorrect options. - (B) Spin movement: Incorrect, as spin transitions are detected in NMR spectroscopy, not IR. - (C) Round movement: Incorrect, as no such term exists in molecular spectroscopy. - (D) All of the above: Incorrect, since only dipole movement is essential for IR spectroscopy. 

Step 4: Selecting the correct option. Since IR spectroscopy requires a change in dipole moment, the correct answer is (A) Dipole movement.