Inorganic - Group 7

Question 1

what is the trend in atomic radius going down group 7?

Answer 1

increases due to each additional electron shell

Question 3

what is the trend in reactivity going down group 7?

Answer 3

• decreases
• as atomic radius increase, it is harder to gain an electron as the positive attraction of the nucleus is weakened by shielding

Question 4

what is the trend in physical properties of the halogens going down the group?

Answer 4

they get darker and denser going down the group

Question 5

why does fluorine have several untypical properties?

Answer 5

because the F-F bond is unexpectedly weak

Question 6

what is the trend in electronegativity going down group 7?

Answer 6

• decreases
• because atomic radii increases down the group so there is more shielding of nuclear attraction

Question 7

what is the trend in melting/boiling point down the halogens?

Answer 7

• increases
• as each element has more electrons, strengthening the van der Waals forces
• this means more energy is required to overcome the intermolecular forces

Question 8

why are the halogens good oxidising agents?

Answer 8

because they accept electrons from the species being oxidised

Question 9

what is the trend in oxidising ability going down group 7?

Answer 9

• decreases
• as their ability to attract electrons decreases due to increased shielding

Question 10

what does the relative oxidising ability mean in terms of halogen displacement reactions?

Answer 10

that a halogen will displace any halide (-ve halogen ion) beneath it in the periodic table

Question 11

what is the trend in reducing ability of halide ions going down the group?

Answer 11

• increases
• as electrons are easier to lose from ions with larger atomic radii due to increasing shielding

Question 12

what can be used to test for halide ions?

Answer 12

acidified silver nitrate