halogens Flashcards
what colour is fluorine?
very pale yellow gas - highly reactive
what colour is chlorine?
greenish, reactive gas - poisonous in high concentrations
trend in melting point down the group
increases down the group, as the molecules become larger they have more electrons and so have larger london forces between the molecules. as the intermolecular forces get larger, more energy has to be put in to break the forces
trend in electronegativity down the grou[
decreases down the group
atomic radii increases down the group due to the increasing number of shells. the nucleus is therefore less able to attract the bonding pair of electrons
electronegativity
relative tendency of an atom in a molecule to attract electrons in a covalent bond to itself
reactivity down the group
decreases down the group as the atoms get bigger with more shielding so they less easily attract and accept electrons. they therefore form -1 ions less easily down the group
oxidation reactions of halide ions by halogens
a halogen that is a strong oxidising agent will displace a halogen that has a lower oxidising power from one of its compounds
oxidising strength down group
decreases, oxidising agents are electron acceptors - more shielding makes it harder to attract electrons
chlorine and potassium chloride
very pale green solution, no reaction
bromine and potassium chloride
yellow solution, no reaction
iodine and potassium chloride
brown solution, no reaction
chlorine and potassium chloride
yellow solution, Cl has displaced Br
bromine and potassium bromide
yellow solution, no reaction
iodine and potassium bromide
brown solution, no reaction
potassium iodide and chlorine
brown solution, Cl has displaced I
potassium iodide and bromine
brown solution, Br has displaced I
potassium iodide and iodine
brown solution, no reaction
potassium chloride (organic) and chlorine
colourless, no reaction
potassium chloride (organic) and bromine
yellow, no reaction
potassium chloride (organic) and iodine
purple, no reaction
potassium bromine (organic) and chlorine
yellow, Cl has displaced Br
potassium bromide (organic) and bromine
yellow, no reaction
potassium bromide (organic) and iodine
purple, no reaction
potassium iodide (organic) and chlorine
purple, Cl has displaced I
