Question

Calculate the atomicity of a gas X( at. no 35.5) whose vapour density is equal to its relative atomic mass.

Answer 1

Answer: The atomicity of the gas is 2.

Explanation:

Let the atomicity of the gas X be y that is teh molecule formula of the gas be $X_y$

The atomic mass of the element X=  35.5

We know that:

Molecular mass of the gas = 2 × vapor density of the gas

$y\times \text{atmoic mass of X}=35.5$

Given that vapor density is equal to its relative atomic mass.

$y\times 35.5=2\times 35.5$

y = 2

The atomicity of the gas is 2.

Answer 2

Answer: The atomicity of X gas is 2.

From the given,

Atomic weight of element = 35.5

Atomic weight is equal to vapour density, therefore, vapour density = 35.5

Solution:

$Atomicity\quad =\quad \frac { Molecular\quad weight }{ Atomic\quad weight }\quad \rightarrow (i)$

$Molecular\quad weight\quad =\quad 2\quad \times \quad Vapour\quad density$

$=\quad 2\quad \times \quad 35.5$

Substitute the values in equation (i)

$Atomicity\quad =\quad \frac { 2\quad \times \quad 35.5 }{ 35.5 } \quad =\quad 2$

Therefore, atomicity is 2.