Soap molecules form micelles in water. The hydrophilic part is:
A. The hydrocarbon tail
B. The entire molecule
C. The carboxylate head
D. The potassium ion
Answer: Option C
Solution (By JKSSB Mock Tests)
The head (–COO⁻) is ionic and attracted to water (hydrophilic). The long hydrocarbon tail is non-polar and hydrophobic, dissolving in grease. This amphiphilic nature allows cleaning.
Explanation:
Amphoteric oxides react with both acids and bases to form salts and water. Aluminum oxide (Al₂O₃) and Zinc oxide (ZnO) are classic examples. Na₂O and MgO are basic oxides that react only with acids, while SO₂ is an acidic oxide that reacts only with bases.
Explanation:
2H₂ + O₂ → 2H₂O is a combination reaction where two or more reactants combine to form a single product. A is decomposition. C is displacement. D is neutralization (also double displacement). Combination reactions are generally exothermic. Another example: C + O₂ → CO₂.
Explanation:
In an acidic medium, potassium permanganate (KMnO4) is reduced to Mn2+. The oxidation state of Mn changes from +7 to +2, a change of 5. The equivalent weight of an oxidizing agent is its molar mass (M) divided by the number of electrons gained per molecule. Thus, Equivalent weight = M/5.
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