Soap works by forming structures called micelles. The hydrophobic tails dissolve in: MCQ with Answer and Explanation

Soap works by forming structures called micelles. The hydrophobic tails dissolve in:
A. The oily dirt
B. Air
C. The soap dish
D. Water
Answer: Option A
Solution (By JKSSB Mock Tests)
The long hydrocarbon chain (tail) of soap is non-polar and hydrophobic, so it dissolves into the oily/greasy dirt particle. The ionic head (hydrophilic) remains in the water. This forms a micelle around the dirt, emulsifying it and allowing it to be washed away. The tail-dirt interaction is via van der Waals forces.

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Practice More chemistry Questions

Question #1
The concentration of dissolved oxygen in water is a measure of its:
A. Acidity
B. Hardness
C. Purity
D. Biological Oxygen Demand (BOD)

Correct Answer: Option D


Explanation:
The amount of dissolved oxygen is crucial for aquatic life. The Biological Oxygen Demand (BOD) is the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material. High BOD indicates high organic pollution and low dissolved oxygen levels.

This question belongs to: Science chemistry
Question #2
Which of the following reactions is NOT a redox reaction?
A. CaCO₃ → CaO + CO₂
B. 2Na + Cl₂ → 2NaCl
C. CH₄ + 2O₂ → CO₂ + 2H₂O
D. Zn + CuSO₄ → ZnSO₄ + Cu

Correct Answer: Option A


Explanation:
In CaCO₃ decomposition, the oxidation states are: Ca (+2), C (+4), O (-2) in both reactant and products, so no change—not a redox reaction. The others involve changes: Zn(0→+2), Cu(+2→0) in B; Na(0→+1), Cl(0→-1) in C; C(-4→+4), O(0→-2) in D. Redox requires change in oxidation numbers.

This question belongs to: Science chemistry
Question #3
Which of the following enzymes is present in tears and kills bacteria?
A. Lysozyme
B. Trypsin
C. Lipase
D. Pepsin

Correct Answer: Option A


Explanation:
Lysozyme is an antibacterial enzyme found in tears, saliva, and egg white. It breaks down bacterial cell walls. Lipase digests fats, trypsin and pepsin digest proteins. Lysozyme is part of the innate immune system.

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