Questions That I Got Wrong With Corrections:
Q10c: Lead forms two ions +2 and +4. Write the formula for the lead chloride that does not include the lead ion with the same charge as the calcium ion.
My Answer: 2Ca+ Pb -> Ca2Pb
Correct Answer: PbCl4 -> I had misinterpreted the question and had just assumed that we were supposed to use the answer from above and create a balanced chemical formula for Calcium and Lead, this was simply my error for not reading the questions properly.
Q11c: For both diamond and graphite, predict a property and explain it linked to its structure and bonding.
My Answer: For diamond, I can predict that it is hard and used for cutting because of its strong intramolecular forces that are hard to break and for graphite, I can predict that it can conduct electricity due to the delocalised electrons in the structure that can carry electrical currents around the atom when charged with an electrical current.
Correct Answer: For diamond, I can predict that it is hard and used for cutting because, for something to be malleable, the atoms have to be able to slide across layers, which is not a possibility for diamond as it has a full structure, with no delocalized electrons or free ions. For graphite, I can predict that it can conduct electricity due to the delocalised electrons in the structure that can carry electrical currents around the atom when charged with an electrical current. -> 1 Mark off because I mentioned the wrong explanation of why diamond is hard.
Q12c: Suggest whether lithium oxide or lithium chloride would have the highest melting point. Explain your choice.
My Answer: Lithium Oxide would have a higher melting point as when lithium oxide is created, it requires 2 lithium atoms opposed to one in lithium chloride, causing a greater lattice of atoms and ion that make the ionic bond stronger, which make it harder to break and melt.
Correct Answer: Lithium Oxide would have a higher melting point as the difference in the charges is greater which enables more electrostatic attraction between the 2 elements. -> 1 Mark off for missing the correct explanation.
Q13b: Pentane boils at 36°C. Explain what happens to the molecules of pentane when liquid pentane boils and becomes a gas.
My Answer: The intermolecular forces between the molecules of pentane break. The covalent bonds don’t break themselves. The weak intermolecular forces allow for quick breaking and low melting/boiling points.
Correct Answer: The intermolecular forces between the molecules of pentane break and the molecules move freely. -> 1 Mark off for missing the second part, dumb mistake as this is something I knew.
Difference Between Intermolecular Forces and Chemical Bonds:
An intermolecular force is a force between molecules in covalent substances, it is not the force that binds the specific atoms together within a covalent molecule but rather the ones connecting the molecules of covalent substances together. However, chemical bonds such as ionic bonding, metallic bonding and covalent bonding (intramolecular forces) all refer to the bond that is directly between the atoms within a molecule of the substance. Ionic bonding specifically refers to the bonding of two oppositely charged ions, metallic bonding refers to the bonding between delocalised electrons and positive ions, and covalent bonding refers to the sharing of a pair of electrons between atoms inside a molecule.