3. Calculate the number of moles and mass in
gram_of_1 x 10^20mdecules of Nz gas
.

0.17×10⁻³ mol

Mass = 0.00476 g

Explanation:

Given data:

Number of molecules of N₂ = 1 ×10²⁰ molecules

Number of moles of N₂ = ?

Mass in gram of N₂ = ?

Solution:

1 mole of any substance contain 6.022×10²³ molecules

1 ×10²⁰ molecules× 1 mol /6.022×10²³ molecules

0.17×10⁻³ mol

Mass in gram:

Mass = number of moles × molar mass

Mass = 0.17×10⁻³ mol × 28 g/mol

Mass = 4.76×10⁻³  g

Mass = 0.00476 g

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.