Which indicator is red in acidic medium and yellow in basic medium?
A. Methyl orange
B. Turmeric
C. Litmus
D. Phenolphthalein
Answer: Option A
Solution (By JKExamLibrary)
Methyl orange is red at pH < 3.1 and yellow at pH > 4.4. Litmus: red in acid, blue in base. Phenolphthalein: colorless in acid, pink in base. Turmeric: yellow in acid, reddish-brown in base.
Explanation:
The 'lock-and-key' model explains enzyme specificity: the substrate fits into the active site like a key in a lock. Protein nature is general; specificity arises from 3D structure.
Explanation:
CO has a triple bond: one sigma and two pi bonds, with a coordinate covalent character where oxygen donates a lone pair to carbon, forming a bond similar to triple bond. Total shared electrons = 6 (three pairs). Lewis structure shows :C≡O: with formal charges. The bond order is 3. It is isoelectronic with N₂ and CN⁻.
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