Question

How many moles of argon are in $452g$ of argon?

Answer 1

Hint: We know that Argon is an element denoted as Ar. It has an atomic number $18$. It is also a noble gas as the atoms of this element have their orbitals full (complete octet). Its valency is $0$. It lies in the group $18$ of the periodic table. It is also the third-most abundant gas in the Earth’s atmosphere.

Complete step by step answer:
We know that the atomic number of Argon is $18$. And the atomic mass of argon is $39.94g$.
We will use the mole concept to determine the moles of argon.
We have the total mass of argon as $452g$.
One mole of argon contains $39.94g$ of argon which is also called the molar mass of Argon.
Thus, n moles of argon contain $452g$ mass of argon.
Thus, to determine the number of moles we will divide the total mass of argon by its molar mass.
$n = \dfrac{{452}}{{39.94}}$
On simplification we get,
$n = 11.31moles$
Therefore, total $11.31moles$ are present in $452gm$ of Argon.

Note:
We must remember that the argon is also called as inert gas due to its unreactive nature. Unlike metals and non-metals. Metals have oxidation state ranging from +1 to +3 thus they can react with other metals to complete their octet. Same is for non-metals as well, the only difference is non-metals have oxidation states ranging from -1 to -3. Mostly, the argon present in the earth’s atmosphere is radiogenic argon-40 which is derived from the decay of potassium-40. Argon is soluble in water. Physically it is colorless, odorless, nonflammable and non-toxic gas. It can exist in three states- as solid, liquid or gas.