Question

12.044 x 10^23 atoms of oxygen contains _______

(a) 1 mole of oxygen

(b) 2 moles of oxygen

(c) 3 moles of oxygen

(d) 4 moles of oxygen

This question was posed to me in final exam.

Origin of the question is Mole Concept and Molar Masses topic in chapter Chemistry Basic Concepts of Chemistry – Class 11

Answer 1

The correct answer is (b) 2 moles of oxygen

The explanation is: One mole of any substance contains Avogadro’s number of particles. Its value is 6.022×10^23 atoms. But here it’s given 12.044 x 10^23 atoms, thereby dividing it by Avogadro’s number; 12.044 x 10^23 atoms/6.022×10^23 atoms = 2 moles. Hence it contains 2 moles of oxygen.