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
what is ka
gives you the relative idea of the strength of the acid
the larger the ka the stronger the acid
pka
tells you how acidic something is
the stronger the acid the lower the pka
the weaker the acid the higher the pka
