Photo AI
The successive ionisation energies of aluminium are presented below - HSC - SSCE Chemistry - Question 35 - 2060 - Paper 1
Question 35
The successive ionisation energies of aluminium are presented below. The ionisation graph shows a steady increase in energy required to remove electrons. Explain ... show full transcript
Worked Solution & Example Answer:The successive ionisation energies of aluminium are presented below - HSC - SSCE Chemistry - Question 35 - 2060 - Paper 1
Step 1
Explain the trend in ionisation energy.
Answer
The ionisation energies for aluminium increase as successive electrons are removed. Notably, there is a significant increase in energy required to remove the fourth electron. This considerable jump occurs because the fourth electron is being removed from a much closer inner shell, which experiences greater attraction from the positively charged nucleus, thus necessitating more energy.
Step 2
Outline the process used to prepare and attach pigments to cave walls.
Answer
To prepare pigments, Aboriginal people would typically gather natural materials such as ochres or charcoal. These materials were then mixed with a binder, such as water, wax, or animal fat, to create a paint-like substance. This mixture could then be brushed or applied directly onto cave walls, where it would adhere and dry.
Step 3
Describe THREE pigments used by Aboriginal people in traditional art, with reference to their chemical composition and colour.
Answer
- Red Ochre: Composed mainly of iron oxide, it provides a deep red colour.
- Yellow Ochre: Similarly, it is an iron oxide with a yellow hue that ranges in brightness based on its composition.
- Charcoal: Typically made from burnt wood, this pigment produces a rich black colour, often used for outlining and details.
Step 4
Step 5
Explain why II and III do not represent the ground state configuration for elemental titanium.
Answer
Configuration II: Fails to adhere to the Aufbau principle as it has electrons placed in the 4s subshell before the 3d is fully filled. Configuration III: This is invalid as it violates Hund's rule; two electrons in the same orbital is incorrect when empty orbitals are available.
Step 6
Outline a valid procedure that could be used to carry out the investigation.
Answer
A suitable procedure involves dissolving a transition metal compound in a suitable solvent, then gradually adding a reagent that influences the oxidation state. The colour changes observed during the addition can indicate the oxidation state, as different states often correspond to different colours.
Step 7
Describe TWO limitations of the procedure outlined in part (i).
Answer
- The colour change may be subtle and difficult to perceive, particularly if other variables interfere.
- There may be instances of overlapping colours due to other chemical reactions, which could mislead the observations and conclusions drawn from the experiment.
Step 8
Explain the role of electrons in determining colour.
Answer
Electrons play a crucial role in determining colour as they transition between energy levels when absorbing or emitting photons. The specific wavelengths of light absorbed correspond to particular electronic transitions, leading to the observable colours. For instance, lower energy transitions may yield red hues, while higher energy transitions might result in blue or violet colours.