Neco Model Questions Vol1 2025 Chemistry Question 16

Practice objective / multiple choice question 16 from the 2025 Neco Model Questions Vol1 Chemistry examination.

Neco Model Questions Vol1 2025 Chemistry Objective / Multiple Choice Hard Difficulty
Question 16 NECO_MODEL_QUESTIONS_VOL1 • 2025 • CHEMISTRY • objective

A wastewater treatment plant receives 5000 m³ per day of effluent containing nitrate ions at a concentration of 30 mg L⁻¹. The treatment consists of two consecutive steps: (i) a biological denitrification stage that removes 60 % of the nitrate present, but 10 % of the nitrate removed is converted to nitrite, which is not removed later; (ii) an ion‑exchange column that removes 80 % of the nitrate remaining after the first stage. Assuming the volume of water does not change, calculate the final concentration of nitrate ions in the discharged water (in mg L⁻¹, to one decimal place).

Answer Options

A. 2.0 mg L⁻¹
B. 1.8 mg L⁻¹
Correct Answer C. 2.4 mg L⁻¹
D. 3.2 mg L⁻¹
Correct Answer
C
Correct Option:
2.4 mg L⁻¹

About This Question

This is Neco Model Questions Vol1 2025 Chemistry Question 16. It is one of the objective questions from the 2025 Neco Model Questions Vol1 Chemistry examination.

Difficulty level: Hard .

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