2016 Atoms, Bonds and Groups Jun

Question 1

Describe the relative energies of the 2s orbital and each of the three 2p orbitals in a nitrogen atom

Answer 1

• P-orbitals have greater energy than s-orbitals

* Three p-orbitals have equal energy

Question 2

Explain how intermolecular forces arise in halogens molecules

Answer 2

• Uneven distribution of electrons
• This creates/causes an instantaneous dipole
•This causes an induced dipole on a
neighbouring halogens

Question 3

Explain why bromine has a higher boiling point than chlorine

Answer 3

• Bromine has more electrons (than chlorine)
• Bromine has stronger (OR more) London forces
(between molecules

Question 4

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Answer 4

•
•Adding (aqueous) barium chloride to bromine (water)
OR
BaCl2 + Br2
M2 Mixing of second pair of solutions
Adding (aqueous) calcium iodide to bromine (water)
OR Cal2 + Br2
OR
Adding aqueous magnesium bromide to aqueous iodine
OR MgBr2 + I2
M3 Colours in cyclohexane
Colour for M1 is orange OR yellow
AND
Colour for M2 is purple OR violet OR mauve OR pink OR
lilac
M4 Ionic equation mark
Br2 + 2I–
 --> I2 + 2Br–

Question 5

Explain the differences in melting points of sodium and magnesium

Answer 5

• Magnesium has more outer OR bonding electrons
• Magnesium ions have a greater (positive) charge
(density
• Magnesium has a greater attraction between ions and
delocalised electrons