Question

The number of sodium atoms in $2{\text{ }}moles$ of sodium ferrocyanide is:

$$A.\;12{\text{ }}X{\text{ }}{10^{23}} \\\ B.\;26{\text{ }}X{\text{ }}{10^{23}} \\\ C.\;34{\text{ }}X{\text{ }}{10^{23}} \\\ D.\;48{\text{ }}X{\text{ }}{10^{23}} \\\$$

Answer 1

We must remember the molecular formula for Sodium ferrocyanide is $N{a_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$. $1{\text{ }}mole$ of the compound is having $4{\text{ }}moles$of$Na$. Generally one mole of a substance is equal to $6.022 \times {10^{23}}$. The number $6.022 \times {10^{23}}$ is known as Avogadro number.

Complete step by step answer:
Let’s start with writing the molecular formula for sodium ferrocyanide. As the name suggests it is a complex compound having 2 components which are metal and a complex. The complex consists of iron $\left( {Fe} \right)$ and cyanide $\left( {CN} \right)$. As we can see the iron is in a ferrous state means having 2+ oxidation states. Also 6 $CN$ are connected with iron so the overall oxidation state of the complex is -4. Hence, 4 $N{a^ + }$ will be attached with the complex and the compounds molecular formula will be $N{a_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$.
$1{\text{ }}mole$ of $N{a_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$ is having $4{\text{ }}moles$ of sodium, and one mole of compound is having $6.022{\text{ }} \times {\text{ }}{10^{23}}$ times the atom. So, $4{\text{ }}moles$ of sodium will be having $4{\text{ }} \times {\text{ }}6.022{\text{ }} \times {\text{ }}{10^{23}}$ atoms.
Similarly, in case of $2{\text{ }}moles$, 2 times the atom in $1{\text{ }}mole$ will be present so, $8{\text{ }}moles$ of sodium will be there and hence $8{\text{ }} \times {\text{ }}6.022{\text{ }} \times {\text{ }}{10^{23}}$ atoms which will be equal to $48{\text{ }} \times {\text{ }}{10^{23}}$ atoms.

So, the answer to this question is D. $48{\text{ }} \times {\text{ }}{10^{23}}$ atoms.

Note: We must know that the Avogadro’s number is being a boon for scientists as it helps in calculating, discussing and comparing very high numbers of atomic and subatomic particles. Avogadro’s number is $6.022{\text{ }} \times {\text{ }}{10^{23}}$. Avogadro’s number becomes very useful because in everyday life the substances contain a large number of atoms and molecules.