Calculate the empirical formula of each of the following substances with the following compositions. a 3.60 g of magnesium and 10.65 g of chlorine

b 9.1 g of lithium and 10.4 g of oxygen

The empirical formula :

MgCl₂

Li₂O

Given

a 3.60 g of magnesium and 10.65 g of chlorine

b 9.1 g of lithium and 10.4 g of oxygen

Required

The empirical formula

Solution

The empirical formula is the smallest comparison of atoms of compound forming elements.

A molecular formula is a formula that shows the number of atomic elements that make up a compound.

(empirical formula) n = molecular formula

a. mol ratio of Mg (Ar=24 g/mol) and Cl(Ar=35.5 g/mol)

Mg : Cl

=3.6/24 : 10.65/35.5

=0.15 : 0.3 = divide by 0.15

=1 : 2

The empirical formula : MgCl₂

b. a. mol ratio of Li (Ar=7 g/mol) and O(Ar=16 g/mol)

Li : O

=9.1/7 : 10.4/16

=1.3 : 0.65 = divide by 0.65

= 2 : 1

The empirical formula : Li₂O

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.

explanation: it gains negative electrons, therefore becoming negatively charged. as charge cannot be created, nor destroyed, only transferred, this leaves the wool positive. now that they have opposite charges, the two items attract.