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Chemistry PYQ NEET UG 2025 · Clear filters

44 questions

Chemistry · PYQ NEET UG 2025

Phosphoric acid ionizes in three steps with their ionization constant values \( \mathrm{K}_{\mathrm{a}_1}, \mathrm{K}_{\mathrm{a}_2} \) and \( \mathrm{K}_{\mathrm{a}_3} \), respectively, while \( \mathrm{K} \) is the overall ionization constant. Which of the following statements are true? A. \( \log \mathrm{K} = \log \mathrm{K}_{\mathrm{a}_1} + \log \mathrm{K}_{\mathrm{a}_2} + \log \mathrm{K}_{\mathrm{a}_3} \) B. \( \mathrm{H}_3\mathrm{PO}_4 \) is a stronger acid than \( \mathrm{H}_2\mathrm{PO}_4^- \) and \( \mathrm{HPO}_4^{2-} \). C. \( \mathrm{K}_{\mathrm{a}_1} > \mathrm{K}_{\mathrm{a}_2} > \mathrm{K}_{\mathrm{a}_3} \) D. \( \mathrm{K}_{\mathrm{a}} = \frac{\mathrm{K}_{\mathrm{a}_3} + \mathrm{K}_{\mathrm{a}_2}}{2} \) Choose the correct answer from the options given below:

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Chemistry · PYQ NEET UG 2025

Given below are two statements : Statement I : Benzenediazonium salt is prepared by the reaction of aniline with nitrous acid at \( 273 - 278\text{ K} \). It decomposes easily in the dry state. Statement II : Insertion of iodine into the benzene ring is difficult and hence iodobenzene is prepared through the reaction of benzenediazonium salt with \( \text{KI} \). In the light of the above statements, choose the most appropriate answer from the options given below :

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Chemistry · PYQ NEET UG 2025

Among the following, choose the ones with equal number of atoms. A. \( 212\text{ g} \) of \( \text{Na}_2\text{CO}_3\text{ (s)} \) [molar mass = \( 106\text{ g} \)] B. \( 248\text{ g} \) of \( \text{Na}_2\text{O (s)} \) [molar mass = \( 62\text{ g} \)] C. \( 240\text{ g} \) of \( \text{NaOH (s)} \) [molar mass = \( 40\text{ g} \)] D. \( 12\text{ g} \) of \( \text{H}_2\text{ (g)} \) [molar mass = \( 2\text{ g} \)]\nE. \( 220\text{ g} \) of \( \text{CO}_2\text{(g)} \) [molar mass = \( 44\text{ g} \)] Choose the correct answer from the options given below :

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Chemistry · PYQ NEET UG 2025

The correct order of decreasing acidity of the following aliphatic acids is : (1) \((\text{CH}_3)_3\text{CCOOH} > (\text{CH}_3)_2\text{CHCOOH} > \text{CH}_3\text{COOH} > \text{HCOOH} (2) \text{CH}_3\text{COOH} > (\text{CH}_3)_2\text{CHCOOH} > (\text{CH}_3)_3\text{CCOOH} > \text{HCOOH} (3) \text{HCOOH} > \text{CH}_3\text{COOH} > (\text{CH}_3)_2\text{CHCOOH} > (\text{CH}_3)_3\text{CCOOH} (4) \text{HCOOH} > (\text{CH}_3)_3\text{CCOOH} > (\text{CH}_3)_2\text{CHCOOH} > \text{CH}_3\text{COOH}\)

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