The halogens are the Group 7 non-metal elements: fluorine, chlorine, bromine, iodine and astatine. They are all poisonous and form diatomic molecules (pairs of atoms joined by a single covalent bond).

True or False? Reactivity decreases as you go down Group 7.

True. As you descend Group 7, each halogen atom has more electron shells, so it is less able to attract an extra electron to complete its outer shell. This makes each successive halogen less reactive .

State the colour and physical state of chlorine , bromine and iodine at room temperature.

Chlorine — pale yellow-green gas Bromine — red-brown liquid Iodine — grey solid (sublimes to form a purple vapour) The colours become darker going down the group.

In a halogen displacement reaction, a more .......... halogen displaces a less .......... halogen from a solution of its halide salt.

In a halogen displacement reaction, a more reactive halogen displaces a less reactive halogen from a solution of its halide salt.

What is observed when chlorine solution is added to potassium bromide solution?

The solution turns orange-yellow as bromine is produced. Chlorine displaces bromide ions because chlorine is more reactive, forming potassium chloride and bromine: Cl 2 + 2KBr → 2KCl + Br 2 .

True or False? Bromine can displace chloride ions from potassium chloride solution.

False. Bromine is less reactive than chlorine , so it cannot displace chloride ions . A halogen can only displace a halide ion of a less reactive halogen from solution.

The melting and boiling points of the halogens .......... as you go down Group 7, due to increasing .......... forces.

The melting and boiling points of the halogens increase as you go down Group 7, due to increasing intermolecular forces.

Define halogen displacement reaction .

A halogen displacement reaction occurs when a more reactive halogen displaces a less reactive halogen from an aqueous solution of its halide salt. It provides evidence for the trend in reactivity in Group 7.

Explain whether astatine would displace iodide ions from potassium iodide solution.

Astatine would not displace iodide ions because it lies below iodine in Group 7 and is therefore less reactive than iodine. Only a more reactive halogen can displace a less reactive one.

IGCSEScienceEdexcelScience (Double Award)ChemistryFlashcards2. Inorganic ChemistryGroup 7 (Halogens)

Group 7 (Halogens) (Edexcel IGCSE Science (Double Award): Chemistry): Flashcards

Exam code: 4SD0

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FrontGroup 7 (Halogens)
Define halogens.
FrontGroup 7 (Halogens)
State the colour and physical state of chlorine, bromine and iodine at room temperature.
BackGroup 7 (Halogens)
Chlorine — pale yellow-green gas
Bromine — red-brown liquid
Iodine — grey solid (sublimes to form a purple vapour)
The colours become darker going down the group.

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Cards in this collection (9)

Define halogens.
The halogens are the Group 7 non-metal elements: fluorine, chlorine, bromine, iodine and astatine. They are all poisonous and form diatomic molecules (pairs of atoms joined by a single covalent bond).
True or False?
Reactivity decreases as you go down Group 7.
True.
As you descend Group 7, each halogen atom has more electron shells, so it is less able to attract an extra electron to complete its outer shell. This makes each successive halogen less reactive.
State the colour and physical state of chlorine, bromine and iodine at room temperature.
1. Chlorine — pale yellow-green gas
2. Bromine — red-brown liquid
3. Iodine — grey solid (sublimes to form a purple vapour)
The colours become darker going down the group.
In a halogen displacement reaction, a more .......... halogen displaces a less .......... halogen from a solution of its halide salt.
In a halogen displacement reaction, a more reactive halogen displaces a less reactive halogen from a solution of its halide salt.
What is observed when chlorine solution is added to potassium bromide solution?
The solution turns orange-yellow as bromine is produced. Chlorine displaces bromide ions because chlorine is more reactive, forming potassium chloride and bromine: Cl₂ + 2KBr → 2KCl + Br₂.
True or False?
Bromine can displace chloride ions from potassium chloride solution.
False.
Bromine is less reactive than chlorine, so it cannot displace chloride ions. A halogen can only displace a halide ion of a less reactive halogen from solution.
The melting and boiling points of the halogens .......... as you go down Group 7, due to increasing .......... forces.
The melting and boiling points of the halogens increase as you go down Group 7, due to increasing intermolecular forces.
Define halogen displacement reaction.
A halogen displacement reaction occurs when a more reactive halogen displaces a less reactive halogen from an aqueous solution of its halide salt. It provides evidence for the trend in reactivity in Group 7.
Explain whether astatine would displace iodide ions from potassium iodide solution.
Astatine would not displace iodide ions because it lies below iodine in Group 7 and is therefore less reactive than iodine. Only a more reactive halogen can displace a less reactive one.

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