Question

One mole of $C{O_2}$contains
A.3-gram atoms of $C{O_2}$
B.18 $\times$ ${10^{23}}$ molecules
C.6 $\times$ ${10^{23}}$ ${\text{O}}$ atoms
D.6 $\times$ ${10^{23}}$ ${\text{C}}$ atoms

Answer 1

In this question, we have to calculate that one mole $C{O_2}$ contains how many entities. Simply use the unitary method and the mole concept to find the answer to this question. The number of entities in a mole depends on Avogadro’s number.

Complete step by step answer:
One mole $C{O_2}$ contains one mole of ${\text{C}}$ atoms and two moles of ${\text{O}}$ atoms. We know that one mole or one-gram atom = $6.022 \times {10^{23}}$atoms. Now let us find the answer to this question:
One mole of $C{O_2}$ ​= one mole of C = $6.022 \times {10^{23}}$atoms of C.
One mole of $C{O_2}$ ​= two moles of O =$2 \times 6.022 \times {10^{23}}$atoms = $12.044 \times {10^{23}}$atoms of oxygen.
Also, one mole of $C{O_2}$ = $6.022 \times {10^{23}}$molecules of $C{O_2}$. And, one mole of $C{O_2}$ = 1 mole of ${\text{C}}$ atoms + 2 mole of ${\text{O}}$ atoms = 3 mole atoms
Considering the given options, we can conclude that the correct answer to this question is option B and option D.

Additional Information: The concept that a mole of any substance contains the same number of particles was formed out of research which was conducted by Italian physicist Amedeo Avogadro. Avogadro constant can be defined as the number of molecules, atoms, or ions in one mole of a substance: $6.022 \times {10^{23}}$ per mol. It is derived from the number of atoms of the pure isotope $^{{\text{12}}}{\text{C}}$ in 12 grams of that substance and is the reciprocal of atomic mass in grams.

Note: If you are not able to solve this question use the formula
${\text{No}}{\text{. of moles = }}\dfrac{{{\text{Mass of the Substance in grams}}}}{{{\text{Molar mass of a Substance}}}} = \dfrac{{{\text{Number of Atoms or Molecules}}}}{{6.022 \times {{10}^{23}}}}$
We are given moles of $C{O_2}$=1 so we can simply calculate the number of atoms by multiplying the no. of moles with the Avogadro’s number. No. of atoms of ${\text{O}}$=2. Thus, the number of atoms of oxygen in one mole will be equal to $2 \times 6.022 \times {10^{23}}$atoms. Similarly no. of carbon atoms in one mole will be equal to $6.022 \times {10^{23}}$atoms.