reaction of aqueous ions Flashcards
write the formula of a metal aqua ion (2+ and 3+ charges)
[M(H2O)6] 2+
[M(H2O)6] 3+
why are aqueous metal ions acidic
- the aqueous metal ion is polarising
- pulls electron density off H2O ligands
- weakens O-H bond
(water ligands can be deprotonated
how many water ligands are deprotonated for 2+ and 3+ metal aqua ions
2 for 2+ ions
and
3 for 3+ ions
explain why deprotonated metal aqua ions are insoluble
they have no overall charge
explain why [M(H2O)6] 3+ ions are more acidic than [M(H2O)6] 2+ ions
smaller and more highly charged so has high charge density so very polarising so pulls more electron density off of water ligands
easier to deprotonate water ligands in 3+ ions
write an equation for the reaction of aqueous Cu2+ ions with NaOH
[Cu(H2O)6] 2+ + 2OH- —> Cu(H2O)4 (OH)2 + 2H2O
write an equation for the reaction of aqueous Co3+ with dilute NH3
[Co (H20)6 ] 3+ + 3NH3 —> CO (H2O)3 (OH) 3 (s) + 3NH4+
what is the colour of aqueous [Cu (H20)6 ] 2+ ions
blue solution
what is colour of aqueous [Fe (H20)6 ] 2+ ions
green solution
what is the colour of aqueous [ Fe (H20)6 ] 3+ ions
brown/purple solution
what is the colour of aqueous [Al (H20)6 ] 3+ ions
colourless solution
write the simplest ionic equation for the reaction of [M (H20)6 ] 2+ ions with sodium hydroxide solution
[M (H20)6 ] 2+ (aq) + 2OH- (aq) —-> M (H2O)4 (OH)2 (s) + 2H2O (l)
write the simplest ionic equation for the reaction of [M (H20)6 ] 3+ ions with sodium hydroxide solution
[M (H20)6 ] 3+ (aq) + 3OH- (aq) —-> M (H2O)3 (OH)3 (s) + 3H2O (l)
give an observation when Fe2+ (aq) reacts with NaOH
green solution –> green ppt —> turns into brown ppt when in air due to oxidation with oxygen to Fe3+
give an observation when Cu2+ (aq) reacts with NaOH
blue solution —> blue ppt
give an observation when Fe3+ (aq) reacts with NaOH
brown/purple solution —> brown ppt
give an observation when Al3+ (aq) reacts with NaOH
colourless solution —> white ppt
write the simplest ionic equation for the reaction of [M (H2O)6 ] 2+ ions with ammonia solution
[M (H2O)6 ] 2+ (aq) + 2NH3 (aq) —> M (H20)4 (OH)2 (s) + 2NH4+ (l)
write the simplest ionic equation for the reaction of [M (H2O)6 ] 3+ ions with ammonia solution
[M (H2O)6 ] 3+ (aq) + 3NH3 (aq) —> M (H20)3 (OH)3 (s) + 3NH4+ (l)
what happens when excess ammonia is reacted with Cu2+ (aq)
and give equation for the reaction
blue ppt —> royal blue solution
[Cu (H2O)6] 3+ (aq) + 4NH3 —> [Cu (H2O)2 (NH3)4 ] 2+
due to a ligand displacement reaction
Write the simplest ionic equation for the reaction of [M (H2O)6 ] 3+
2 [M(H2O)6 ] 3+ (aq) + 3CO3 2- (aq) ——> 2M (H2O)3 (OH)3 (s) + 3H2O + 3CO2
What observation is made when M3+ ions react with sodium carbonate solution
Bubbles/ effervescence due to CO2 production
Explain why [M (H2O)6 ]2+ ions do not react with sodium carbonate solution
[M (H2O)6 ] 2+
Why can Al(OH)3 be described as amphoteric
Acts as both an acid and a base
When happens when excess NaOH is added to Al3+ (aq) ppt
Precipitates redissolves, because Al3+ ions more acidic and can further deprotonated
Al(OH)3 acts as an acid
Write the simplest ionic equation for the reaction of [M(H2O)6 ] 2+ with sodium carbonate solution
M(CO3) + 6H2O
write the equation for when Al (H2O)3 (OH)3 reacts with excess NaOH
Al (H2O)3 (OH)3 + OH- —-> [Al (H2O)2 (OH)4 ]- + H2O
write the equation for when Al (H2O)3 (OH)3 reacts with excess HCl
Al (H2O)3 (OH)3 + 3HCl —–> AlCl3 + 6H2O
define a bronstead lowry acid
proton ( H+) donor
define a bronstead lowry base
proton (H+) acceptor
put these bases in order of their strength
NH3
NaOH
Na2CO3
NaOH ( OH-) strong base
NH3 (NH3) weak base
Na2CO3 ( CO3 2-) very weak base
what will sodium carbonate deprotonate
stronger M3+ ions
not M2+ ions
define a lewis acid
electron pair acceptor
define lewis base
electron pair donor
what colour is FeCO3
green ppt
what colour is CuCO3
blue/green ppt
what 3 ways can the exam board refer to aqueous metal ions
- aqueous metal ions
- aqua metal ions
- metal aqua ions
what 2 factors affect the relative acidity of metal ions
size
charge
(charge density which then affects polarisability)
write the product formed when aqueous aluminium reacts with excess NaOH
[Al (H2O)2 (OH)4 ]-
write the product formed when aqueous aluminium reacts with excess NH3
Al (H2O)3 (OH)3