Mole Concept

Mediumchemistry

A sample contains 3.011×10⁺23 atoms of an element. Its mass is 12 g. The element is:

Select the correct option:

Magnesium

Carbon

Aluminium

Oxygen

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About This Question

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

Solution

Correct Answer:

Magnesium

Find Number of Moles:
- $n = \frac{N u mb er o f a t o m s}{N _{A}} = \frac{3.011 \times 1 0 ^{23}}{6.022 \times 1 0 ^{23}} = 0.5 m o l$ .
Calculate Molar Mass:
- $M o l a r ma ss = \frac{M a ss}{M o l es} = \frac{12 g}{0.5 m o l} = 24 g / m o l$ .
Identify the Element:
- Magnesium ( $M g$ ) has a molar mass of $24 g / m o l$ .
- (Carbon is 12, Aluminium is 27, Oxygen is 16).

This medium 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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