Acids and Alkalis Flashcards
What are ionic charges of metals in Group 1, 2 and 3
If they are in group 1 they must lose 1 electron, group 2 must lose 2 and group 3 they must lose 3 to have a full outer shell. If they are in group 2 they have 2 on the outer shell so must lose 2 the have a full outer shell. They are now positively charged because they lost electrons. If you lost one electron you are +1 (positive).
What are the ionic charges of non-metals in Group 5,6,7
If they are in group 7, they have 7 electrons on the outer shell, they must gain 1 as there are 8 in an outer shell. They are negatively charged because they gained 1 electron.
Ion charges of: silver copper 2 irons lead zinc
Ag+ Cu2+ Fe2+ Fe3+ Pb2+ Zn2+
Charge of Hydrogen Hydroxide ammonium carbonate nitrate sulfate
hydrogen H+ hydroxide OH- ammonium NH4 has a + ion carbonate CO3 has a 2- ion nitrate NO3 has a - ion sulfate SO4 has a 2- ion
What are acids in an Aqueous solution?
Hydrogen ions
What are alkalis in an Aqueous solution?
Hydroxide ions
What is neutralisation?
Acids can neutralise alkalis, even them out and visa versa.
Solubility rules
Silver and lead chloride in insoluble
barium, calcium and lead sulfate are insoluble
all carbonates are insoluble apart from sodium potassium and ammonium
hydroxides are insoluble apart from sodium potassium and calcium
everything else is soluble
Making a salt by Neutralisation
Take an appropriate acid,
then add a reactive metal
or base, oxide, hydroxide, or carbonate.
If it is an insoluble base or metal you must use excess base method.
If it is a soluble base base or metal you must use titration
Making a soluble salt from an insoluble base or metal
Excess bass method
Measure out volume of acid solution and add a spatula of solid metal, metal oxide, metal hydroxide and metal carbonate. Warm the beaker
Continue adding solid metal into the solution until no more can be dissolved, warm and stir reaction to make sure the reaction is complete.
Filter of the excess solid and collect the filtrate, a pure salt solution
Evaporate the solution two thirds over a water bath.
Leave it to cool, so it crystallises and pat down with filter paper
Making a soluble salt from a soluble bass or metal
Titration
Measure out volume of alkaline solution, 20cm cubed. Add phenolphthalein indicator.
Run acid into the flask from a burette, add a drop at a time until its one drop away form turning pink to colourless. It is now neutralised. Note down the amount of acid needed to neutralise (reading on burette)
Repeat process without indicator and add the exact amount need to neutralise.
Evaporate two thirds of the solution over a water bath and then leave to cool so it crystallises. Pat dry with filter paper.
Acids and bases in terms of proton transfer
A hydrogen atom has no neutron so it only has protons and electrons.
An acid is a proton (hydrogen) donor
A base is a proton (hydrogen) acceptor
When an acid reacts with a base the acid loses its hydrogen atom and the base accepts it
