chem 621 exam
acid is a substance from which a proton, H+, can be removed and a base is a substance that can remove a proton, H+, from an acid
Bronsted-Lowry theory
acid is a substance that dissociates in water to produce a H3O+ ion and base is a substance that dissociates in water to OH-
Modern Arrhenius Theory
temperature
a change in what is the only stress that will change the value of the equilibrium constant?
buffer
a solution that contains a weak acid/conjugate base can act as a
amphoteric
a substance that can act as both an acid and a base
exothermic
acids added to water is an extremely what reaction
monoprotic, diprotic, triprotic acid
an acid that contains only one, two, or three hydrogen ion(s) that can dissociate is called what
group one or two
any what metal make a strong base
buffers
can resist changes in pH
oxoacid
contains H+ and a polyatomic ion that contains water
acid is a substance that dissociates to produce one or more H+ ions and base is a substance that dissociates to produce one or more OH- ions
define acid using the Arrhenius Theory
isolated
equilibrium can only be reached in what kind of system?
HCN
exception to the binary acid definition
ions add acid-use part of buffer add base-use other part of buffer uses up H+ or OH-
how do buffers resist changes in pH when small amounts of acid or base are added
product
if equilibrium is reached after a long time there will be a lot of what
product
if equilibrium is reached early or quickly there be very little what
equivalent point
in a titration the point when the number of moles of base equal the number of moles of acid is the
standard solution
in a titration the solution of known volume and concentration is called
HCLO4, H2SO4, HI, HBR, HCL, HNO3
list the 6 strong acids
liquid or solid
never include particles in which states in an equilibrium constant expression
dynamic equilibrium
occurs when opposing forces are working at the same time and the same rate
left to right
reactions are always read (fwd rxn)
a system at equilibrium tends to respond so as to relieve the effect of any change in the conditions that effect equilibrium
state Le Chateliers's Principle
at equilibrium, there is a constant ratio between the concentrations of the products and the reactants in any change
state the law of chemical equilibrium
end point
the colour change in a titration
1.0×10-7
the concentration of H3O+ in water is what
equilibrium constant?
the constant ratio between the concentration of products and reactants when a system is in equilibrium
products
the larger the Ka, the more the what are favoured in the reaction
electronegative
the more what an element is, the easier it is for a H+ to dissociate
oxygen
the more what atoms a molecule contains the stronger the acid strength
equivalent points
the nearly vertical line on a titration curve shows the
Buret
the piece of glassware that allows the user to control the volume of acid or base added in a titration is called the
reactants
the smaller the Ka, the more what are favoured in the reaction
2
the titration of a diprotic ot dibasic substance would show how many equivalence points
3
the titration of a triprotic or tribasic substance would show how many equivalence points
chemical equilibrium
the type of equilibrium that occurs when the rate of formation of products is equal to the rate of formation of reactants
Vapour Equilibrium
the type of equilibrium when the number of molecules vaporizing is equal to the number of molecules condensing is
solution equilibrium
the type of equilibrium when the number of particles dissolving is equal to the number of particles returning to crystal form
reactant quotient, Qc
the what tells you in which direction the reaction must proceed to reach equilibrium?
weaker
the what the bond, the easier the hydrogen ion can pull away from the atom
tastes bitter, conducts electricity, and can neutralize an acid
three properties of a base
tastes sour, will conduct electricity, and can neutralize a base
three properties of an acid
litmus paper or indicators
two ways to measure pH are to use
binary acid
what acid contains 2 different elements
rate of opposing changes is equal, observable properties of a system at eq are constant, be in an isolated system, and get from someone with review sheet
what are the 4 conditions that apply to all equilibrium systems?
concentration, temperature, catalysts, and pressure
what are the 4 stresses on a chemical reaction?
physical and chemical
what are the two types of equilibrium?
solution and vapour
what are the two types of physical equilibrium?
acid-base pair
what do the acid and conjugate base make
Always Add Acid to water
what does AAA stand for
the concentrations are approximately equal
what does Kc=1 mean?
the products are favoured
what does Qc<Kc mean?
the system is at equilibrium
what does Qc=Kc mean?
the reactants are favoured
what does Qc>Kc mean?
conjugate acid
what does a base turn into in a reaction
concentration of the products is greater than the concentration of the reactants
what does a large Kc (Kc>1) mean?
the concentration of the reactants is greater than the concentration of the products
what does a small Kc (Kc<1) mean?
completely ionizes or dissociates
what does a strong acid or strong base do in water
slightly ionizes or dissociates
what does a weak acid or weak base do in water
conjugate base
what does an acid turn into in a reaction
potential of hydrogen
what does pH stand for
1.0×10-14
what is Kw
Kw=[H3O+][OH-]
what is the equation for Kw
indicator
what is used to show the endpoint by the colour change in the titration
close to one or one
when the ratio of a buffer's weak acid/conjugate base or vice versa is what value, then the buffer has reached it's maximum
one way arrow
which arrow does a reaction with a strong acid or base have
two way arrow
which arrow does a reaction with a weak acid or base have
hydrogen attached to the oxygen atom
which hydrogen is most easily lost
reverse reaction
which reaction is read right to left
when product molecules collide with the proper angle and sufficient energy to overcome the reactant barrier they will reform the products
why are reactions reversible?
get answer from someone with review sheet
why does a system reach equilibrium?
small Kc means the equilibrium favours the reactants so only a small amount of the reactants will become products, an amount so small it can be ignored
why is the small Kc rule useful to know?
