Group 7

Question 1

Appearance of Cl2 at room temperature

Answer 1

Green gas

Question 2

Appearance of Br2 at room temperature

Answer 2

Red-brown liquid

Question 3

Appearance of I2 at room temperature

Answer 3

Black solid

Question 4

Disproportionation

Answer 4

A reaction where the same element is both reduced and oxidised

eg Chlorine and water:

Question 5

oxisdising power of halides

Answer 5

• decreases down the group
• due to ability to attract electrons (electronegativity) decreses due to the incresing number of shells
• Cl
• Br
• I
• displace the ones below eachother

Question 6

atomic radius

Answer 6

• increases down the group
• incresed sheliding
• less attraction

Question 7

bleach

Answer 7

made from cold aq NaOH + Cl2

Question 8

reducing power

Answer 8

• increases down the group
• greater the reducing power the longer the reaction as the halide is powerful to reduce more species

Question 9

tests for ions

with silver nitrate

Answer 9

• Cl - white ppt
• Br - cream ppt
• I - yellow ppt

Question 10

dissolving in ammonia

Cl , Br , I

Answer 10

• Cl - dissloves in dilute and concentrated
• Br - only dissolves in concenrated
• I - does not dissolve

Question 11

What is the test for HCl?

Answer 11

Turns blue litmus paper red