What state and colour is Chlorine at room temp?
pale green
gas
What state and colour is Bromine at room temp?
red-brown
liquid
What state and colour is Iodine at room temp?
dark grey
solid
What are diatomic models?
molecules made from pairs of atoms
How do you test for chlorine?
Insert damp litmus paper into a test tube containing a gas
If the gas is chlorine, the litmus paper will bleach and change colour from red to white
What happens as you go down group 7 (the halogens) on the periodic table?
the elements get less reactive
Group 0 elements (noble gases)
unreactive
full outer shell of electrons
low boiling point
low density
Sodium + chlorine —>
Sodium chloride
Metal + halogen —>
Metal halide
A H+ ion is…
acidic
A H- ion is…
alkaline
What is a spectator ion?
An ion that does not change in the reaction
Oxidation is…
loss
Reduction is…
gain
Electrolytes
ionic compounds that dissolve in water to make a solution that conducts electricity
Positively charged ions move to the…
cathode
Negatively charged atoms move to the…
anode
When an ion touches an electrode…
electrons can be transferred
What happens when ionic compounds are dissolved in water?
The charged ions become free to move
The liquid/solution will conduct electricity
Non-metal ions will be attracted to the…
anode
Metal ions will be attracted to the…
cathode
When simple ionic compounds are heated, will they melt?
yes
What are two disadvantages of electrolysis to extract metals?
lots of energy required
expensive
When extracting metals with electrolysis, where does the carbon dioxide form?
At the anode
When extracting metals with electrolysis, where does the extracted metal form?
At the cathode
Why does electrolysis use up a lot of energy?
Because you have to melt the solid ionic compound and provide the electrical current