GCSE Spec Flashcards - All Topics
What term can be used to describe all forces of attraction between molecules
Intermolecular forces
Describe molecule
What is the important half equation for the production of oxygen in solution electrolysis
4OH- -> O2 + 2H2O +4e-
What are the reactions of group 1 elements in water
All of them:
Solid floats - it is less dense than water.
Effervescence - hydrogen gas is produced.
Solid moves - the effervescence propels it around the surface of the water.
Solid disappears - it is used up in the reaction
Lithium - see above
Sodium - melts
Potassium - lilac flame
Why does group 1 get more reactive as you go down the group?
When a group 1 metal atom reacts, it loses its outer-shell electron to get a full outer shell.
This happens more easily down the group because:
1. The atoms get bigger and have more shells
2. The outer-electron is further from the nucleus
3. The attraction between the nucleus and the outer-electron is weaker
4. So less energy is needed to break the attractio
Describe the colour and state of the group 7 elements
Fluorine F2 Very pale yellow (g)
Chlorine Cl2 Pale green (g)
Bromine Br2 Brown (l) Volatile, releases brown fumes
Iodine I2 Dark grey (s) Sublimes, releases purple fumes
Astatine At2 Black (s
Halogen Displacement:
What colour is chlorine?
Colourless
Halogen Displacement:
What colour is bromine?
Yellow
Halogen Displacement:
What colour is iodine?
Brown
Halogen Displacement:
What colour is Potassium chloride?
Colourless
Halogen Displacement:
What colour is potassium bromide?
Colourless
Halogen Displacement:
What colour is potassium iodide?
Colourless
Halogen Displacement:
What colour is KCl + Cl2?
Colourless
= No change
Halogen Displacement:
What colour is KCL + Br2?
Stays yellow
= No change because bromine is not reactive enough to displace chlorine
Halogen Displacement:
What colour is KCL + I2?
Stays Brown
= No change because iodine is not reactive enough to displace chlorine
Halogen Displacement:
What colour is KBr + Cl2?
Colourless -> Yellow
Because chlorine displaces bromine to form bromine which is yellow
Halogen Displacement:
What colour is KBr + Br2?
No change
Halogen Displacement:
What colour is KBr + I2?
Stays brown
= No change because Iodine is not reactive enough to displace bromine
Halogen Displacement:
What colour is KI + Cl2?
Colourless -> brown
Chlorine displaces iodine to form iodine which is brown
Halogen Displacement:
What colour is KI + Br2?
Yellow -> brown
Because Bromine displaces iodine to form iodine which is brown
Halogen Displacement:
What colour is KI + I2?
No change
Combustion of magnesium in oxygen
Bright white light
White solid formed
Combustion of hydrogen in oxygen
Water formed
Squeaky pop
Combustion of sulphur of oxygen
Blue flame
