Neco Model Questions Vol1 2025 Chemistry Question 3

Practice objective / multiple choice question 3 from the 2025 Neco Model Questions Vol1 Chemistry examination.

Neco Model Questions Vol1 2025 Chemistry Objective / Multiple Choice Medium Difficulty
Question 3 NECO_MODEL_QUESTIONS_VOL1 • 2025 • CHEMISTRY • objective

In the diagram of a gas‑collection‑over‑water apparatus, a gas is collected at a volume of \(250.0\ \text{mL}\) at \(25.0^{\circ}\text{C}\). The barometric pressure is \(760\ \text{mmHg}\) and the vapour pressure of water at this temperature is \(23.8\ \text{mmHg}\). After drying, the gas volume is measured as \(242.0\ \text{mL}\) at \(1.00\ \text{atm}\) and \(298\ \text{K}\). Determine the number of moles of the original gas collected over water.

Answer Options

A. 1.1×10⁻³ mol
B. 1.0×10⁻² mol
C. 8.5×10⁻³ mol
Correct Answer D. 9.9×10⁻³ mol
Correct Answer
D
Correct Option:
9.9×10⁻³ mol

About This Question

This is Neco Model Questions Vol1 2025 Chemistry Question 3. It is one of the objective questions from the 2025 Neco Model Questions Vol1 Chemistry examination.

Difficulty level: Medium .

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