4.2 - Group 7 Flashcards
Colour, State and formula of Fluorine
Very pale yellow, gas, F2
Colour, State and formula of Chlorine
Pale green, gas, Cl2
Colour, State and formula of Bromine
Brown, liquid, Br2
Colour, State and formula of Iodine
Dark Grey, Solid, I2
Colour, State and formula of Astatine
Black, solid, At2
What do halogens form when they react with metals
Ionic compounds
Define ionic bonding
The strong electrostatic attraction between a positive and negative ion
Define covalent bonding
The strong electrostatic attraction between a pair of shared electrons and the positive nuclei
What kind of reaction is a reaction between a metal and a halogen
Redox reaction
(Metal loses electrons)
(Halogen gains electrons)
In a reaction with a metal what does the halogens name change to
Halogen -> Halide
Fill the Gap
Halogens get …. Reactive down the group
Less
Fill the Gap
Colours get …. Down the group
Darker
Fill the Gap
Boiling/melting point …. Down the group
Increases
Fill the Gap
All halogen atoms need to …. An electron to fill their ….
Gain, outer shell
Why is it more difficult for a halogen to gain an electron as you go down the group
Atoms have more electron shells
The extra electron is further away from the nucleus
So its attraction to the nucleus is weaker
Why is it easier for a metal to lose an electron as you go down the group
Atoms have more electron shells
The extra electron is further away from the nucleus
So its attraction to the nucleus is weaker and can be lost easier
What does the group show on the periodic table
Number of electrons in outer shell
(The electrons GROUP together)
What does the period show on the periodic table
The number of electron shells
What does the period show on the periodic table
The number of electron shells
Test for chlorine
Damp blue litmus paper in gas turns white
Because chlorine acts as a bleaching agent so it removes the colour from the paper
Fill the Gap
…reactive halogens can displace … reactive halogens from their compounds
More, less
What colour is aqueous (aq) Chlorine and what is it
Colourless
Halogen
What colour is aqueous (aq) Bromine and what is it
Yellow
Halogen
What colour is aqueous (aq) Bromine and what is it
Yellow
Halogen
What colour is aqueous (aq) Iodine and what is it
Brown
Halogen
What colour is aqueous (aq) KCl (Potassium Chloride) and what is it
Colourless
Salt
What colour is aqueous (aq) KBr (Potassium bromide) and what is it
Colourless
Salt
What colour is aqueous (aq) KI (Potassium Iodide) and what is it
Colourless
Salt
KCl + Cl2
No change
Stays colourless
KCl + Br2
No change
Bromine cannot displace chlorine
Stays yellow
KCl + I2
No change
Iodine cannot displace chlorine
Stays brown
KBr + Cl2
Cl2 + 2KBr —> Br2 + 2KCl
Chlorine displaces bromine
Colourless -> Yellow
KBr + Br2
No change
Stays yellow
KBr + I2
No change
Stays brown
KI + Cl2
Cl2 + 2KI —> I2 + 2KCl
Chlorine displaces iodine
Colourless -> brown
KI + Br2
Br2 + 2KI —> I2 + 2KBr
Bromine displaces iodine
Yellow -> brown
KI + I2
No change
Stays brown
Fill the gap
Displacement occurs in the three cells becuase the halogen added is …. Reactive than the halogen present in the …
More, salt
True/False
The reactivity trend in halogen is Chlorine > Bromine > Iodine > etc
True
