Chemistry Task 8 Prac

Question 1

Structure of Water

Answer 1

• Water has the chemical formula H2O, meaning each water molecule contains 1 oxygen and two hydrogen
• They bond by sharing electrons, meaning the intermolecular bonds are covalent
• Each oxygen has two lone pairs that contribute to the molecule’s shape, the bent shape
• The covalent bonds are polar in water due to oxygen having higher electronegativity than hydrogen atoms

Question 2

Hydrogen bonding in water

Answer 2

• Hydrogen bonding is the main type of intermolecular force in water
• It occurs due to the electrostatic attractions between the partial positive charge on a hydrogen atom to the lone pairs in neighbouring water molecule’s oxygen.
• Because of the large electronegativity difference between water and oxygen, the partial charges on water are large
• The hydrogen bonds are quite strong

Question 3

Group 16 hydrides

Answer 3

• Group 16 elements such as oxygen, sulfur, selenium, tellurium and polonium can bond with hydrogen to form the group 16 hydrides.
• Water is a group 16 hydride
• Their melting a boiling points reflect the size of the forces between their molecules
• The higher their boiling and melting points are the higher the intermolecular forces is due to the amount of energy it takes to break the bonds