Question

Gram molecular mass of Oxygen is $32g$. The density of Oxygen is $1.429\;g/litre$. Find the gram molar volume of Oxygen.
(A) $22.4\,L$
(B) $11.2\,L$
(C) $5.6\,L$
(D) $44.8\,L$

Answer 1

Gram molecular mass and density of oxygen are given. To calculate the gram molecular volume of the oxygen we have to use the relation between density, mass, and volume.

Formula Used: The density of an entity is given by the relation:
$d = \dfrac{m}{V}$
Where $d$ is the density of that entity
$m$is the mass in grams of the entity and $V$ is the volume in liters.

Complete step by step answer:
Oxygen is a member of the halogen family of group $16$. Its atomic number is $8$. It has six unpaired electrons in its valence shell which makes oxygen one of the most electronegative elements in the entire periodic table.
The molecule of oxygen is composed of two oxygen atoms bonded together with a double bond with lone pairs of electrons.
The gram molecular mass is defined as the mass of one molecule of a given substance. It is equal to the molecular weight of the substance or the sum of all the atomic masses present in the molecular formula. The only difference between molar mass and gram molecular mass is of the unit which is used to express both parameters.
Now, we are given the Gram molecular mass of oxygen $= 32$
The Density of oxygen $= 1.429g/litre$
And we have to calculate the density, so we will use the relation between density, mass, and volume.
The density of oxygen will be as from the relation:
$d = \dfrac{m}{V}$
$V = \dfrac{m}{d}$
$V = \dfrac{{32}}{{1.429}} = 22.4\,l$
Hence, the gram molecular volume of oxygen will be $22.4\,l$

Therefore, option (A) is correct.

Note:
Gram molecular volume is the volume that is occupied by $1$ gram molecular weight of any substance at the $STP$ i.e. Standard temperature and pressure conditions. The Temperature and pressure at $STP$ are $273\,K$and $1\,bar$.