Air Water And Soil Pollution Effects

Water vapour is a greenhouse gas and contributes to global warming, so statement (A) is incorrect.
CFCs are strong greenhouse gases and hence contribute to global warming, making statement (C) incorrect.
HFCs also contribute to global warming, so statement (D) is incorrect.
Statement (B) is correct because CO2 fertilization generally increases plant productivity by enhancing photosynthesis.
Final Answer: (B)

Step 1: Check statement (A).
Phosphorus is a limiting nutrient in freshwater ecosystems; excess causes eutrophication. This statement is correct.
Step 2: Evaluate statement (B).
Phosphorus in rocks exists mainly as inorganic phosphates (e.g., apatite). Organic phosphates occur in living organisms, not rocks. Hence (B) is incorrect.
Step 3: Evaluate statement (C).
Unlike carbon and nitrogen cycles, the phosphorus cycle has no gaseous phase. Phosphorus does not volatilize and thus cannot move long distances through the atmosphere. Therefore (C) is incorrect.
Step 4: Check statement (D).
Excessive use of fertilizers leads to runoff into rivers and oceans; this is correct.
Thus, the NOT correct statements are (B) and (C).
Final Answer: (B), (C)

Step 1: Statement I.
- Cr(III) = low solubility, low mobility. - Cr(VI) = high solubility, highly mobile. Hence, Statement I is correct.
Step 2: Statement II.
- Reaction with zero-valent iron reduces hexavalent chromium (Cr VI) → trivalent chromium (Cr III). - It does not produce Cr(VI). Hence, Statement II is incorrect.
Step 3: Statement III.
- Cr(VI) is highly toxic and a known carcinogen. Hence, Statement III is correct.
Step 4: Statement IV.
- Cr(III) is an essential trace element, less toxic. - Cr(VI) is far more toxic. Hence, Statement IV is incorrect.
Step 5: Conclusion.
Correct statements = I and III → Option (C). Final Answer:

Step 1: Dalton’s Law.
Dalton’s Law states that the total pressure of a gas mixture equals the sum of partial pressures of individual gases. So:
Step 2: Fick’s Law.
Fick’s Law deals with molecular diffusion, where flux is proportional to the concentration gradient. So:
Step 3: Henry’s Law.
Henry’s Law describes the equilibrium relation between gas concentration in liquid and its partial pressure in gas phase, i.e., gas-liquid transfer. So:
Step 4: Stoke’s Law.
Stoke’s Law gives the settling velocity of spherical particles in a fluid under laminar conditions, i.e., gravitational settling. So:
Step 5: Match and Verify.
This corresponds to Option (A). Final Answer: