MAQA AS CHEMISTRY PAPER 1:
INORGANIC AND PHYSICAL
CHEMISTRY
Give the full electron configuration of an Al atom and a Cr3+ ion - 1s2 2s2 2p6 3s2 3p1
1s 2s2 2p6 3s2 3p6 3d6
Deduce the formula of the ion that has a charge 2+ with the same electron - Sr2+
Deduce the formula of the compound that contains 2+ ions and 3- ions that both have the same electron
configuration as argon - CaP
Deduce which of Na+ and Mg2+ is the smaller ion 2 marks - Mg 2+
Both have the same number of shielding however Mg2+ has more protons so higher nuclear charge and
so stronger attraction between out electrons and nucleus so smaller atomic radius
First ionisation of sodium - Na(g) -> Na+ + e-
Explain why the first ionisation of sulfur is lower than phosphorus 4 marks - Sulfur has a pair of electrons
in its 3p orbital
Phosphorus has 3 unpaired electrons in its 3p orbital
Pair of electrons repel and electron is easily removed
Less energy is needed to remove the electron
This question is about a white solid MHCO3 that dissolves in water and reacts with HCl to give a salt
Samples of the solution were titrated
Student identified burette as the largest source of uncertainty in the experiment. Suggest how the
procedure could be improved to reduce the percentage uncertainty in using the burette
Justify your suggested improvement 2 marks - Use larger mass of solid
So larger reading will be needed
A student is required to make up 250cm3 of an aqueous solution that contains a known mass of MHCO3.
The student is provided with a sample bottle containing the MHCO3.
Describe the method including apparatus and practical details that the student should use to prepare the
solution. 6 marks - - weigh sample bottle containing solid on a balance
, - Transfer to volumetric flask and reweigh sample bottle
- record difference in mass
- add distilled water
- stir with glass rod
- rinse all remaining solid from sample bottle into flask
- transfer to volumetric flask with 250 cm3 mark
- with washing make up to 250 cm3
- shake
Melting point Boiling point
Br 266. 332
Mg 923. 1383
In terms of structure and bonding explain why the bop of Br is different from Mg. Suggest why Mg is a
liquid over a much greater temperature range compared to Br 5 marks - 1) Br is a simple molecular
structure
2) Mg is a metallic structure
3) Br2 weak van der waals forces between molecules
4) more energy needed to over come stronger metallic bonds
5) Mg greater liquid range because forces of attraction in molten metal stronger than Br2
Explain how ions are accelerated, detected and have their abundance determined in the time of flight
(TOF) mass spectrometer - Ions accelerated by electric field
Ions hit the detector gains an electric and forming a current
Abundance detected by size of current
Suggest one reason why the experimental value is very different from the data book value 1 mark - Heat
loss to the surroundings
Name the type of bond formed between N and Al in H3NAlCl3 and explain how this bond is formed 2
marks - Covalent bond
Shared pair of electrons from N
INORGANIC AND PHYSICAL
CHEMISTRY
Give the full electron configuration of an Al atom and a Cr3+ ion - 1s2 2s2 2p6 3s2 3p1
1s 2s2 2p6 3s2 3p6 3d6
Deduce the formula of the ion that has a charge 2+ with the same electron - Sr2+
Deduce the formula of the compound that contains 2+ ions and 3- ions that both have the same electron
configuration as argon - CaP
Deduce which of Na+ and Mg2+ is the smaller ion 2 marks - Mg 2+
Both have the same number of shielding however Mg2+ has more protons so higher nuclear charge and
so stronger attraction between out electrons and nucleus so smaller atomic radius
First ionisation of sodium - Na(g) -> Na+ + e-
Explain why the first ionisation of sulfur is lower than phosphorus 4 marks - Sulfur has a pair of electrons
in its 3p orbital
Phosphorus has 3 unpaired electrons in its 3p orbital
Pair of electrons repel and electron is easily removed
Less energy is needed to remove the electron
This question is about a white solid MHCO3 that dissolves in water and reacts with HCl to give a salt
Samples of the solution were titrated
Student identified burette as the largest source of uncertainty in the experiment. Suggest how the
procedure could be improved to reduce the percentage uncertainty in using the burette
Justify your suggested improvement 2 marks - Use larger mass of solid
So larger reading will be needed
A student is required to make up 250cm3 of an aqueous solution that contains a known mass of MHCO3.
The student is provided with a sample bottle containing the MHCO3.
Describe the method including apparatus and practical details that the student should use to prepare the
solution. 6 marks - - weigh sample bottle containing solid on a balance
, - Transfer to volumetric flask and reweigh sample bottle
- record difference in mass
- add distilled water
- stir with glass rod
- rinse all remaining solid from sample bottle into flask
- transfer to volumetric flask with 250 cm3 mark
- with washing make up to 250 cm3
- shake
Melting point Boiling point
Br 266. 332
Mg 923. 1383
In terms of structure and bonding explain why the bop of Br is different from Mg. Suggest why Mg is a
liquid over a much greater temperature range compared to Br 5 marks - 1) Br is a simple molecular
structure
2) Mg is a metallic structure
3) Br2 weak van der waals forces between molecules
4) more energy needed to over come stronger metallic bonds
5) Mg greater liquid range because forces of attraction in molten metal stronger than Br2
Explain how ions are accelerated, detected and have their abundance determined in the time of flight
(TOF) mass spectrometer - Ions accelerated by electric field
Ions hit the detector gains an electric and forming a current
Abundance detected by size of current
Suggest one reason why the experimental value is very different from the data book value 1 mark - Heat
loss to the surroundings
Name the type of bond formed between N and Al in H3NAlCl3 and explain how this bond is formed 2
marks - Covalent bond
Shared pair of electrons from N
