Module 6

Question 1

Why can polar molecules dissolve in water?

Answer 1

They are particularly water and
can form strong enough attractions to ions to permit
dissolving

Question 2

Describe how London forces are caused?

Answer 2

-A fluctuation in electron density in a non-polar molecule cause an instantaneous dipole
-This induces a induced dipole in a neighbouring molecule
-This forms an instantaneous-induced dipole
-The forces between the two molecules are called London forces

Question 3

What effects the strength of London forces?

Answer 3

number of electrons

Question 4

Does HI or HBr have a high boiling point? Explain reasoning

Answer 4

HI as it has more electrons the HBr, making the London forces stronger and increasing the amount of energy needed to overcome the forces. (Despite HBr having a larger dipole)

Question 5

What force do all molecules have?

Answer 5

London forces

Question 6

Properties of simple covalent molecules

Answer 6

-Low melting and boiling points
-Do not conduct electricity (no free charged particles to move to other molecules)