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
when balancing electrons in KOHES reactions you…
example:No3- +4H+ —>No+ 2 H2O
you put (how much difference)e- to the side that has the most
answer: No3- +4H+ +3e- —>No+ 2 H2O
in KOHES s stands for…. what what do you do
states. in this step you add the steps remember hydrogen ions always in aq form
what is water’s high heat capacity?
Water has a high heat capacity due to the large amount of hydrogen bonding between water molecules.
heat capacity
how much energy is required to heat that 1g of that substance by 1 degree
latent heat of fusion (Lf)of water
the amount of energy needed to change a fixed amount of water from a solid to liquid phase at 0 °C
latent heat of vaporisation (Lv) of water
is the amount of energy needed to change a fixed amount of water from a liquid to a gas at 100 °C
what does the latent heat tell us
The higher the latent heat of a substance, the greater the amount of energy it needs when it changes state
what is latent heat
the energy is needed when a substance changes states (for example, when ice melts and becomes water, or water becomes water vapour),.
what does q= n x L stand for
q= heat energy in kj
n= mole
L= latent heat value of fusion or vaporisation( kj/mol)
what are precipitation reactions
when chemicals in a reaction react to form a solid
Solubility
is the extent to which a solute dissolves in a solvent.
An insoluble substance is…
one that does not dissolve
A soluble substance is..
one that readily dissolves in a particular solvent.
Kinetic Molecular Theory of
Gases? 5 facts
- Gases are made up of particles moving constantly and at random.
- Gas particles are very far apart, and the volume of the particles is very small compared with the volume that the gas occupies.
- The forces of attraction and repulsion between gas particles are practically zero.
- Gas particles collide with each other and the walls of their container, exerting pressure. The collisions are perfectly elastic. This means that no kinetic energy is lost when they collide.
- The higher the temperature, the faster the gas particles move, because they have increased kinetic energy.
calculating pressure formulas to get Kpa
when you have mmHg what do u do…
when you have atm what do u do….
mmHg:
(given value)/750 x100
atm:
(given value)/0.987 x100
Charles law is
when pressure is constant the volume of gas is directly proportional to its temperature V1/T1=V2/T2
boyle law is
P1V1=P2V2
general gas equation PV=nRT rearranges for volume mole and temp
V=nRT/P
n=PV/RT
T=PV/nR
%v/v formula
A
volume of solute in mL/volume of solution in mL X100
%m/v formula
mass of solute in grams/volume of solution in L X100
concentration in grams per litre(gL-)
mass of solute in grams/volume of solution in litres
concentration in milligrams per litre(mgL-)
mass of solute in milligrams/volume of solution in litres
Parts per million formula
ppm=mass of solute in micrograms/mass of solution in grams
%m/m formula
mass of solute in grams/mass of solution in grams X100
neutralisation reaction
acid +base = salt and water
eg
HCL+ NaOH—> NaCl + H2O
salts
K2SO4
and NaOH
neutralisation reaction process
take the negative from the acid and positive from the base and make salt make sure same amount is taken eg n2- g2+
when acids are reacted with metal carbonate they form
salt water carbon dioxide CO2
rf value
distance moved by solute / by solvent
