Fechar
Explain how the ions are held together in solid sodium metal.
(1 mark)
Explain how ions are held together in solid sodium chloride.
(1 mark)
The melting point of sodium chloride is much higher than that of sodium metal. What can be deduced from this information?
(1 mark)
Compare the electrical conductivity of solid sodium metal with that of solid sodium chloride. Explain your answer.
(3 marks)
Explain why sodium metal is malleable.
(1 mark)
In terms of electrons involved, explain how the bond between the BF3 molecule and the F- ion is formed. Name the type of bond formed in this reaction.
(2 marks)
Explain why the bond angle in an amide ion (NH2-) is smaller than that in an ammonia molecule (NH3).
(2 marks)
Describe the bonding that is present in metals.
( 3 marks)
Explain how the bonding and structure lead to the typical metallic properties of electrical conductivity and malleability.
(4 marks)
Suggest a reason why aluminium is a better conductor of electricity than magnesium.
(2 marks)
Define the term electronegativity.
(2 marks)
Name the strongest type of intermolecular force present in:
- Liquid F2
- Liquid CH3F
- Liquid HF
(3 marks)
Explain how the strongest type of intermolecular force in liquid HF arises.
(3 marks)
The boiling points of some hydrogen halides are HCl - 188, HBr - 206 and HI - 238. Explain the trend in boiling points of the hydrogen halides from Hcl to HI.
(2 marks)
Explain why the O-H bond in a methanol molecule is polar.
(2 marks)
The boiling point of methanol is 65, the boiling point of oxygen is -183. Methanol and oxygen both have an Mr of 32. Explain in terms of the intermolecular forces, why the boiling point of methanol is much higher than that of oxygen.
(3 marks)
Why do diamond and graphite both have high melting points?
(3 marks)
Explain why magnesium has a higher melting point than sodium.
(2 marks)
Why is graphite a good conductor of electricity?
(1 mark)
Why is graphite soft?
(2 marks)
By reference to all the atoms involved, explain in terms of electrons how Na2S is formed from its atoms.
(2 marks)
What change occurs to the motion of the ions in sodium chloride when it is heated from room temperature to a temperature below its melting point?
(1 mark)
A chloride ion has one more electron than a chlorine atom. In the formation of sodium chloride, from where does this electron come?
(1 mark)
What property of the atoms joined by a covalent bond causes the bond to be polar?
(1 mark)
Give the name of the type of bond formed when phosphine (PH3) reacts with an H+ ion. Explain how this bond is formed.
(3 marks)
State and explain the trend in electronegativity values across Period 3 from sodium to chlorine.
(3 marks)
Why is each bond angle exactly 120 in BCl3?
(2 marks)
Give the name which describes the shape of molecules having bond angles 109. Give an example of one such molecule.
(2 marks)
Describe the motion of the particles in solid iodine and in iodine vapour.
(3 marks)
Explain why solid iodine vaporises when warmed gently.
(2 marks)
Silver and sodium chloride melt at similar temperatures. Give 2 physical properties of Ag which are different from those of NaCl and give a reason for the difference.
(4 marks)
When considering electron pair repulsions in molecules, why does a lone pair of electrons repel more strongly than a bonding pair?
(1 mark)
Name the type of force that holds the particles together in an ionic crystal.
(1 mark)
What is a covalent bond?
(1 mark)
State how a coordinate bond is formed.
(2 marks)
What is a permanent dipole?
(2 marks)
Explain why a molecule of hydrogen chloride is polar?
(2 marks)
Name the type of force that exists between molecules of chlorine.
(1 mark)
Why is there no hydrogen bonding between molecules of HBr?
(1 mark)
By referring to the types of intermolecular force involved, explain why energy must be supplied in order to boil liquid HCl.
(3 marks)
State what is meant by the term polar bond.
(1 mark)
Suggest the strongest type of intermolecular force present in pure sulphuric acid (H2SO4). Briefly explain how this type of intermolecular force arises.
(2 marks)
State the bond type in sodium oxide and the bond type in sulphur dioxide. In each case, explain the link between the bond type and the electronegativity of the elements involved.
(4 marks)
Coordinate bonding can be described as dative covalency. In this context, what is the meaning of each of the terms covalency and dative?
(2 marks)
Why is sodium chloride ionic rather than covalent?
(2 marks)
Why is aluminium chloride covalent rather than ionic?
(2 marks)
Why is molten sodium chloride a good conductor of electricity?
(1 mark)
Explain, in terms of covalent bonding, why the element iodine exists as simple molecules whereas the element carbon does not.
(3 marks)
Describe the nature and strength of the bonding in solid calcium oxide.
(3 marks)
Use the kinetic theory to describe the changes that take place as calcium oxide is heated from 25 degrees to a temperature above its melting point.
(3 marks)
State two properties of calcium oxide that depend on its bonding.
(2 marks)
State one feature which molecules must have in order for hydrogen bonding to occur between them.
(1 mark)
Give the name of the type of intermolecular bonding present in H2S, and explain why hydrogen bonding does not occur.
(2 marks)
State and explain the similarities and differences in electrical conductivity of sodium, graphite and diamond.
(4 marks)
State which one of the elements neon, sodium, magnesium, aluminium and silicon has the lowest melting point and explain your answer in terms of the structure and bonding present in that element.
(3 marks)
State which one of the elements neon, sodium, magnesium, aluminium and silicon has the highest melting point and explain your answer in terms of the structure and bonding present in that element.
