Elements Of The Sea (ES)

Question 1

halogens

Answer 1

most reactive group of non-metals, none found naturally in elemental form, diatomic

Question 2

physical appearance at rt

Answer 2

F - pale yellow gas
Cl - green gas
Br - dark red volatile liquid
I - shiny grey/black solid (purple vapour on warming)

Question 3

trends in halogens down the group

Answer 3

darker in colour, melting + boiling point increase, gases to liquid to solid, becomes less volatile.

Question 4

displacement reaction

Answer 4

species displaces or pushes out less reactive species from a compound

Question 5

oxidation state increases when:

Answer 5

loss of electron (oxidised) or gain of oxygen

Question 6

oxyanion

Answer 6

negative ion with oxygen in it (end in -ate)

Question 7

dynamic equilibrium

Answer 7

a state of balance where opposing forces or factors occur simultaneously at equal rates. concentrations stay constant, rate of forward and reverse reactions are the same. (reversible reaction)

Question 8

risks of chlorine

Answer 8

toxic gas, can irritate eyes and skin. at higher concentrations it can react in the lungs to form HCl and causing drowning.

Question 9

% atom economy =

Answer 9

(relative formula mass of desired product / relative formula mass of all reactants used) x 100