FC10

Question 1

Sate and explain 2 anomalous properties of water which result from its hydrogen bonding.

Answer 1

*Relatively high mpt and bot compared to molecules of similar size
*because H-bonding is stronger than other intermolecular forces
*so more energy needed to overcome these forces and separate water molecules.

*Water is less dense as a solid than as a liquid
*because solid water (ice) has an open lattice structure
*caused by H-bonds being directional as they must point towards lone pairs
*so average, the space between molecules in ice are bigger than in water

Question 2

Explain how induced dipole-dipole forces arise in iodine.

Answer 2

*The electrons in the I2 molecule are constantly moving around.

*At any time there could be an uneven distribution of electrons along the molecule causing an instantaneous dipole.

*The partial negative charge of the instantaneous dipole repel the electrons in the adjacent I2 molecule causing an induced dipole.

*The opposite charges of the adjacent molecules attract and form an induced dipole-dipole force

Question 3

Name of shape and bond angle with 2 electron density around central atom

Answer 3

Linear

180 degrees

Question 4

Name of shape and bond angle with 3 electron density around central atom

Answer 4

Trianon planar

120 degrees

Question 5

Name of shape and bond angle with 4 electron density around the central atom

Answer 5

Tetrahedral

109.5 degrees

Question 6

Name of shape and bond angle with 4 electron density, 3 bond angle airs and 1 lone pair, around the central atom

Answer 6

Pyramidal

107 degrees

Question 7

Name of shape and bond angle with 4 electron density, 2 bond angle airs and 2 lone pair, around the central atom

Answer 7

Non- linear

104.5 degrees