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?