Mole Concept

Easychemistry

How many molecules of water are present in 0.25 mol of H2O?

Select the correct option:

1.5×10⁺23

2.5×10⁺22

4.5×10⁺23

6.0×10⁺22

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About This Question

Subject: chemistry
Chapter: some basic concepts in chemistry
Topic: mole concept
Difficulty: Easy
Year: 2025

Solution

Avogadro's Number ( $N_{A}$ ): $1 m o l = 6.022 \times 1 0^{23}$ particles.
Calculate Molecules:
- $T o t a l m o l ec u l es = M o l es \times N_{A}$
- $T o t a l m o l ec u l es = 0.25 m o l \times 6.022 \times 1 0^{23} m o l^{- 1}$
- $T o t a l m o l ec u l es \approx 1.5055 \times 1 0^{23}$ .
Scientific Notation: Rounding correctly for the options gives $1.5 \times 1 0^{23}$ molecules.

This easy difficulty chemistry question is from the chapter some basic concepts in chemistry, covering the topic of mole concept. It appeared in the 2025 exam.

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