psyhochemical properties Flashcards
characteristic of bases:
taste bitter
feel slippery
contain hydroxide ions
poisonous and corrosive to skin
characteristics of acid:
- they have a sour taste
- react with metals
3..contain hydrogen - poisonous and corrosive to skin
what is the arrhenus definition of acids and bases
Acid- it contains hydrogen ion which dissociates in water to form hydroxide ions
bases-it contains hydroxyl group and dissociate in water to form a hydroxyl ion
what is the bronsted lowry definition?
acid: it loses a proton of H+
bases: accepts a proton of H+
what is conjugated ?
conjugated bases is a basic form of a given acid . if it accepts the proton it will become an acid
conjugated acid is a basic form of given base if it loses a proton it becomes the base
the weaker the acid the stronger its conjugated base
the stronger the acid the weaker its conjugated base
what is a ph
ph is potential hydrogens
it measures the acidity of a solution
it also measures the amount of hydrogen ions present in solution
the more hydrogen ions present the lower the Ph
ph is measured using -log10 (H+) ions
what is a strong acid?
it fully ionises in solution
eg Hcl
Hno3
h2so4
hbr
what is a strong bases ?
ionises in water soluble
eg
koH
NaOH
weak acid?
partially ionises in solution eg vinegar
hco3
weak base
partially ionises in water
eg nh3
f
no2
how to conjugate an acid or base
to conjugate an acid its add H+ increase charge
conjugate a base loses an H+ loses the charge
what is kw i
Dissociation of water
whats the log ph
ph= -log10 (H3O+)
ph scale
on the ph scale , lower than 7 ph acidic
7 is neutral and more than 7 its alkaline basic
lemon juice is ph 3
water is ph 7
whats poh
Poh measures the hydroxide ion
ph= -log10 (oh-)
kw never changes
what does ph and poh always equal
ph + poh = 14
what is water?
water is amphetric which means its both acid and a base as it loses and accepts proton.
what is autonisation of water?
if theres two water molecules the oxygen is negative and hydrogen is a positive charge . if under any circumstance the two different water molecules come closer together the positive hydrogen gets attached to negative oxygen.
So now one water particle gets 3 hydrogens and becomes hydronium HO3-
The other water molecule remain with one hydrogen and becomes an OH- ion.
one molecule loses its proton and the other one gains a proton.
this is also the equiliriam
The equation-
2H20 reversible arrows H3O+ +OH-
What happens when you add an acid or base to water
when you add acid to water it increases H+
when add base to water it loses h+
what does pure water dissociates in?
it dissociates in 25 degreess room to yeild 10-7 moles/L OF H+ or H30+
whats the kw equations?
kw= h+ x oh-/ h20
the ph of a solution depends on 2 things
the concentration of the solution= if you have 2 solution of the same acid the more concentrated one will have more hydrogen ions so lower ph
the acid- if you have 2 acids the same the more stronger acid will have lower ph than a weak acid as it fully dissociates and produces h+ ions
lewis definition of acid and base?
acid: electron pair acceptor
base- electron pair donor
what is neutralisation
when an acid and base react together to make salt and water
