Chemistry Validation 27/March/25

Question 1

“Physical” Properties: of Lithium’s melting/boiling points

Answer 1

Melting Point; 180.5C
Boiling point; 1,342C
High Thermal energy required to break strong electrostatic attraction.

Question 2

Lithium’s conductivity

Answer 2

High-Due to free moving mobile charge which can carry electrical current easily

Question 3

“Chemical” Properties: of Lithium’s ionisation energy

Answer 3

5.4 eV (relatively low) - Due to its large atomic radius and proton to electron ratio. Weak nuclear attraction on the outer shell and strong shielding effect.

Question 4

Lithium’s electronegativity

Answer 4

0.98 (Pauling Scale) Low - The outermost electron is far from the nucleus. The inner two electrons shield the nuclear charge, so the outer electron doesn’t feel the full pull of the nucleus.

Question 5

“Mechanical/Optical properties: of Lithium’s hardness

Answer 5

0.6 (Moh’s Scale - Very Soft) - Atoms are large and loosely packed, making the metallic bonds weak and easy to break.

Question 6

Lithium’s brittleness

Answer 6

Yes, lithium chloride (LiCl) is a brittle substance, like other ionic compounds, because of the way its crystal lattice structure breaks down under stress. BUT LITHIUM ITSELF IS NOT BRITTLE.

Question 7

“Physical” Properties of Bromine’s/Melting and Boiling points

Answer 7

Melting point of -7.2C and a boiling point of 58.8C

Question 8

Bromine’s conductivity

Answer 8

Very poor conductor of electricity because they don’t have free-moving charged particles like electrons or ions, which are necessary to conduct

Question 9

“Chemical” Properties of Bromine: Ionisation energy

Answer 9

Bromine has 35 protons, which gives it a strong nuclear charge pulling electrons in.

This contributes to a high attraction between the nucleus and outer electrons, making it harder to remove an electron.

Question 10

Bromine’s electronegativity

Answer 10

Very High. Bromine has a high effective nuclear charge and needs just one more electron to complete its outer shell (like all halogens).

However, it’s less electronegative than chlorine (3.16) and fluorine (3.98) because:

Its valence shell is farther from the nucleus (n=4)

It has more inner electron shielding

Question 11

Bromine’s mechanical/optical properties: Hardness

Answer 11

N/A because it’s a liquid at room temperature

Question 12

Bromine’s brittleness

Answer 12

Can’t be brittle. because its liquid at room temp

Question 13

BLAST FURNACE equations

Answer 13

Combustion of Carbon (Coke) Step 1; C + O2 = CO2

Step 2; CO2 + C = 2CO

Step 3: Reduction of Iron Ore (Haematite or Magnetite)
Carbon monoxide reduces iron(III) oxide (Fe₂O₃) or Fe₃O₄ to iron (Fe).

Using Haematite - Fe2O3
Fe2O₃ + 3CO = 2Fe + 3CO2

Using Magnetite (Fe₃O₄):
Fe₃O₄+4CO=3Fe+4CO₂

Question 14

Oxidisation:

Answer 14

It’s the loss of electrons from a substance. It’s also the gain of oxygen by a substance. A common example is Magnesium is oxidised when it reacts with oxygen to form magnesium oxide

Question 15

Reduction - (Redox)

Answer 15

Reduction - (Redox). It’s the gain of electrons by a substance. It’s also the loss of oxygen from a substance. It involves when Oxygen is removed like when Fe2O3 converts from iron oxide to elemental PURE iron.