Exam revision Flashcards
what is the bronsted-lowry theory ?
when an acid loses a proton(donates) and a base gains a proton(accepts)
what are amphiprotic substances?
can react as both acid and base example:water
What are polyprotic acids?
acids that can donate more than one proton
What are monoprotic, diprotic, and triprotic acids?
acids that only donate one proton, two and three
equation for diprotic, and triprotic acids include
- double arrows not full ionisation meaning it is weak
-multiple steps to fully ionise
ph scale trends
middle is neutral the strongest acid is ph 1 strongest base ph 14
if concentration of H3o+ > OH- the solution is…
if concentration of H3o+ < OH- the solution is…
if concentration of H3o+ = OH- the solution is…
acidic
basic
neutral
if we know the pH of a solution and want to work of the concentration H3o+ or OH-
for acid:
example:pH 2
concentration of H3o+=10^-2
=0.01M
for base:
example:
step 1: [H3o+]pH=2
=10^-2=0.01M
step 2:[OH-]=10^-14/[H3o+]=10^-14/10^-2
=10^-12
if we know the concentration of a solution and want to work of the pH H3o+ or OH-
for acids:
[H3o+]=o.oo1M
=10^-3
pH=-log10(10^-3)
=-(-3)
=3
for base:
[H3o+]=10^-14/[OH-]
example:
10^-14/10^-3=10^-11
pH=-log10(10^-11)
pH=11
oxidation and reduction (oil rig)
oxidation is the loss of oxygen reduction is the gain of oxygens
when oxidation number increases =
when oxidation number decreases =
oxidisation has occured causing the loss of electrons making that element the reductant/reducing agent
reduction has occured causing the gain of electrons making the element the oxidant/ oxidising agent
how to find oxidation numbers
by adding up the charges from the valance electrons if the element is by itself than its charge is 0.
Charges of elements on the periodic table
conjugate pairs for redox reactions structure
oxidising agent first/reductant agent
half equation if its reduction electrons are placed …and if oxidation they are placed…
reduction=left/beginning oxidation=right/end
2H+ charge=…
+2
-e is placed on the side….
that has more electrons
when doing the key element step in KOHES all you need to do for Br2…
would be 2Br-
when doing the balance of oxygen step (in a kohes reaction) you need to…
for example: when you have No3- —>No
add a water molecule
answer:No3- —>No+ 2 H2O
–>since the other side already has one oxygen it need two more
when the balance of hydrogen in a KOHES reaction you…
example:No3- —>No+ 2 H2O
add hydrogen ions to the side that needs it for balance
answer:No3- +4H+ —>No+ 2 H2O