Unit 5 - Halogens Flashcards Preview

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Flashcards in Unit 5 - Halogens Deck (14)
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1
Q

State and colour of fluorine at room temperature

A

Pale yellow

Gas

2
Q

State and colour of chlorine at room temperature

A

Very pale green

Gas

3
Q

State and colour of bromine at room temperature

A

Red / brown

Liquid

4
Q

State and colour of iodine at room temperature

A

Purple / black

Solid

5
Q

State and colour of astatine at room temperature

A

Black

Solid

6
Q

Difference between hydrogen chloride and hydrochloric acid

A

Hydrogen chloride is a gas, and has the formula HCl(g). When hydrogen chloride dissolves in water, hydrochloric acid is formed. This has the same formula, but you can tell the difference because of the state symbol (aq), which stands for ‘aqueous’.

7
Q

Why is hydrogen chloride acidic in water but not methylbenzene

A

When hydrogen chloride gas dissolves in a solvent like methylbenzene, the molecules do not split up. A solution of HCl in methylbenzene does not contain hydrogen ions, so it is not acid

8
Q

Describe an experiment to show a more reactive halogen will displace a less reactive halogen from a solution of one of its salts

A

Add the halogen to the solution, a colour change will indicate a displacement.

Eg. Sodium bromide (clear) + chlorine (vv pale green) would make sodium chloride (clear) + bromine (brown)

9
Q

What is another term for displacement reaction

A

Redox

10
Q

Test for the anion Cl-

A

Use dilute nitric acid and silver nitrate solution.

A white precipitate is formed

11
Q

Test for anion Br-

A

Use dilute nitric acid and silver nitrate solution.

A cream precipitate is formed

12
Q

Test for anion I-

A

Use dilute nitric acid and silver nitrate solution.

A yellow precipitate is formed

13
Q

Simple test for chlorine gas

A

Makes damp blue litmus paper turn red, then bleaches it white

14
Q

What group is also known as the halogens

A

Group 7 (fluorine, chlorine etc)