C8 - Reactivity Trends Flashcards
What state are each of the halogens in at room temp (F, Cl, Br, I)
F - gas
Cl - gas
Br - liquid
I - solid
What does F look like at room temp
Very pale yellow gas
What does Cl look like at room temp
greenish gas
What does Br look like at room temp
red liquid
What does I look like at room temp
shiny grey solid
What is the trend in melting point for group 7 elements?
Melting point increases down the group
Bigger molecules, more electrons, stronger london forces
more energy required to overcome
The halogens higher in the group (F and Cl) are MORE POWERFUL ___ ___ than those lower in the group (Br and I)
oxidising agents
State and explain the role halogens play in redox reactions
Oxidising agents
They gain electrons (so are reduced - RIG) meaning they oxidise the other species
During a displacement reaction, chlorine becomes the free halogen. What colour is the solution in the test tube?
Very pale green (often colourless)
During a displacement reaction, bromine becomes the free halogen. What colour is the solution in the test tube?
Yellow
During a displacement reaction, iodine becomes the free halogen. What colour is the solution in the test tube?
Brown (sometimes black solid)
A displacement reaction occurs between a halide and a halogen, the colour of the solution is not immediately obvious, what could you do to change this?
Add an organic solvent and shake, a coloured precipitate will form in the solvent clearly indicating the free halogen
During a displacement reaction, chlorine becomes the free halogen. An organic solvent is added. What colour is the solution in the solvent?
colourless
During a displacement reaction, bromine becomes the free halogen. An organic solvent is added. What colour is the solution in the solvent?
Yellow
During a displacement reaction, iodine becomes the free halogen. An organic solvent is added. What colour is the solution in the solvent?
purple