Statement 1 is correct: Acetylene is extensively used in the welding industry due to the high flame temperature of the oxyacetylene flame (up to 3200°C), making it ideal for cutting and welding metals. Statement 2 is correct: Acetylene is a key raw material for preparing plastics, such as polyvinyl chloride (PVC) and polyacetylene, through processes like polymerization and addition reactions. Statement 3 is incorrect: Acetylene can be obtained by reacting calcium carbide (CaC₂) with water, producing acetylene and calcium hydroxide as by-products. This is a simple and efficient industrial method. (Note: Silicon carbide is not involved in acetylene production.) UPSC GS Paper-I PYQs 610 Direction: The following item consists of two statements. One labeled as the ‘Assertion (A)’ and the other as. ‘Reason (R)’. You have to answer this item using the code given below: 357. Assertion (A): Formic acid is a stronger acid than acetic acid. Reason (R): Formic acid is an organic acid.
✓ Correct answer: b) Both A and R are true but R is not the correct explanation of A
ExplanationAssertion (A) is true: Formic acid (HCOOH) is indeed a stronger acid than acetic acid (CH₃COOH).The difference arises because formic acid lacks the electron-donating methyl group (-CH₃) present in acetic acid.This absence makes formic acid’s proton release (ionization) easier, enhancing its acidity.Reason (R) is true: While formic acid is an organic acid, this fact does not explain why it is stronger than acetic acid.Acidity is determined by the molecular structure and not merely by virtue of being organic.358
Practice more Science PYQs
Attempt a free 10-question quiz or browse the full Science & Technology previous-year-question bank with instant answers and explanations.
🔬 Science PYQs →