electron bonding and structure(exam questions)

Describe what is meant by ionic lattice in terms of particle of types and arrangement of particles present ? (2)

• Repeating pattern

• Oppositely charged ions

What is meant by the term covalent bond? (1)

• The sharing of one pair of electrons between 2 atoms

What is a dative covalent bond ? (1)

• special type of covalent bond where one atom provides both shared electrons in the bond

Describe how does van der waals forces arise ? (3)

• Uneven Distribution of electrons

• Causing instantaneous dipole

• Dipole induces another molecule

Describe and explain one anomalous property of water which results from hydrogen bonding? (2)

• Liquid water molecules is denser than solid

• In solid state H20 molecules are held apart by hydrogen bonds cause

Explain the intermolecular forces in H20 that lead to the relatively high boiling point ? (3)

• Hydrogen binds occur in H in one water molecule and a lone pair of an O in another water molecule

• Draw the bonds ,delta (-),delta (+),

• H20 has Hydrogen bonding

Explain why a molecule of NCL3 has this shape and a bond angle of 107 ? (3)

• Electron pairs repel

• Lone pair repel more

• 4 electron pairs surround central atom or 3 bonds and a lone pair

Describe and explain the density of ice compared with water ? (2)

• Ice is less dense than water

• Hydrogen bonds hold h20 molecules apart

Explain why a water molecule has a different shape from a carbon dioxide molecule? (2)

• Electron pairs repel so they go far parts as possible

• H20 has 4 areas of electron density And Carbon dioxide is surrounded by 2 regions of electron density

Water and carbon dioxide both have polar bonds Explain why water has polars molecules but carbon dioxide has non-polar molecules? (2)

• Carbon dioxide dipoles cancel out

• Water dipoles don’t cancel out