Explanation:
As we know ,
One mole of a gas contains 6.023 * 10 ²³ number of atoms .
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
( a ) From the question ,
w = 10 g ,
As we know molecular mass of Hydrogen = 2 g/mol
Using the above formula , and putting the respective values ,
Moles = n ,
n = w / m = 10 / 2 = 5 mol
The number of atoms in one molecule of Hydrogen = 2
Hence ,
The number of atoms = 5 * 2 * 6.023 * 10 ²³ = 60.23 * 10 ²³ atoms .
( b ) From the question ,
w = 10 g
As we know molecular mass of helium gas = 4 g/mol
Using the above formula , and putting the respective values ,
Moles = n ,
n = w / m = 10 /4 = 2.5 mol
The number of atoms in one molecule of Helium = 1
Hence ,
The number of atoms = 5 * 1 * 6.023 * 10 ²³ = 30.115 * 10 ²³ atoms .
( c ) From the question ,
moles of nitrogen gas = 2.5 mol
The number of atoms in one molecule of nitrogen gas = 2
Hence ,
The number of atoms = 2.5 * 2 * 6.023 * 10 ²³ = 30.115 * 10 ²³ atoms .
( d ) From the question ,
w = 110 g
As we know molecular mass of carbon dioxide gas = 44 g/mol
Using the above formula , and putting the respective values ,
Moles = n ,
n = w / m = 110 / 44 = 2.5 mol
The number of atoms in one molecule of carbon dioxide = 3
Hence ,
The number of atoms = 2.5 * 3 * 6.023 * 10 ²³ = 45.17 * 10 ²³ atoms .
( e )
From the question ,
w = 365 g
As we know molecular mass of sulfur hexafluoride gas = 146 g/mol
Using the above formula , and putting the respective values ,
Moles = n ,
n = w / m = 365 / 146 = 2.5 mol .
The number of atoms in one molecule of sulfur hexafluoride gas = 7
Hence ,
The number of atoms = 2.5 * 7 * 6.023 * 10 ²³ = 105.40 * 10 ²³ atoms .
Hence ,
The order is -
sulfur hexafluoride > Hydrogen > carbon dioxide > nitrogen gas = helium gas
