Questions I Got Wrong (paper1) Flashcards
Why can a substance conduct electricity as a liquid but not conduct electricity as a solid
Ions that are fixed in position in a solid are mobile in liquids. It also had no delocalised electrons so that’s why it cannot conduct electricity as a solid.
What ions are present when acids dissolve in water
OH-
Predict the reactivity of beryllium compared with magnesium
Beryllium is less reactive
As the attractive between magnesium’s outer shells and nucleus is weaker therefore it’s more reactive as it has less shells.
Why is granite soft
As each carbon atom is covalently bonded to 3 other carbon atoms. It arranged in layers which can easily slide over one another as the layers have weak forces of attraction between them. Not a lot of pressure is needed to break it down.
Why is diamond hard
Each carbon is covalently bonded to 4 other carbons leaving no delocalised electrons. Diamond also is very rigid and due to covalent bonds being strong it has a high BP and MP as a lot of energy is needed to break down those strong bonds.
Why does graphite conduct electricity
Each carbon in graphite is covalently bonded to 3 other carbons leaving one delocalised electron per atom to carry an electric current through graphite. The electric current can travel through the layers and the whole structure.
Why can aluminium not be extracted by heating aluminium oxide with carbon
As aluminium is more reactive than carbon
Explain why aluminium forms at the negative electrode during electrolysis
Aluminium is attracted to the negative electrode as aluminium ions are positive. So they are attracted to the cathode and gain a electron at the cathode.
Why does carbon dioxide form at the positive electrode during electrolysis
Oxygen is produced at the anode during electrolysis and this oxygen turn reacts with the carbon and firm carbons dioxide.
How can any unreacted iron can be separated from the mixture
Through filtration
Explain which element is reduced between the reaction through magnesium and iron chloride
3Mg + 2FeCl3 - 2Fe + 3MgCl2
Mg - Mg2+ + 2e-
Fe3+ + 3e- -Fe
Iron is being reduced so it gains electrons. Magnesium is being oxidised so electrons are lost.
How did mendeleevs periodic table change
He left gaps and spaces for elements not found yet and so the groups were arranged correctly as the properties of each group was the same
Why do some elements have low BP such as chlorine, fluorine and bromine
They have weak forces between molecules that doesn’t take much energy to overcome
Why is neon unreactive
Neon is unreactive as it has a full outer shell and it’s electronic strict is 2,8 so it therefore us unreactive.
