Acids, Bases and Constants - created from Mind Map

Orders of reaction 1st order 2nd order 0th order Rate determining step rate of reaction is directly proportional to the concentration of substance Rate=k[X] Rate of reaction is directly proportional to the square of the concentration of the substance Rate=k[X]^2 Rate of reaction is not proportional to the concentration of the substance, but the substance is still necessary for the reaction to take place Rate=k[X]^0 The slowest step in the reaction is what is considered the rate determining step. the other steps are so fast comparatively, that to concentrations of the reactants have no overall effect on the rate of reaction

Kc General Formula: aA + bB cC dD Kc= ([C]^(c)[D]^(d) / [A]^(a)[B]^(b) Kc is the equilibrium constant the Kc for a reaction is constant if temperature is constant Changing concentrations of reactants/products in equilibrium will have no effect on the value of Kc Pressure also has no effect on Kc, for the same reasons that concentration doesn't When Kc is greater than one. Then the position of equilibrium, moves to the RHS. When it is below one, it moves to the LHS Kc value changes with temperature, because temperature causes the concentrations of the reactants/products to change is the concentration of one of the substances is changed, then the position of equlibirum will shift to produce more on the other side of equation, until a new dynamic equilibrium forms with the same Kc

Acids and bases in bronsted-lowry theory, bases are proton acceptors, and acids are proton donors When an acid dissolves into water, it disassociates into positive hydrogen ion and a negative ion. HAH+ + A- Ph is a measure of the concentration of H+ ions in solution. Ph= - Log10[H+] Ka is the disassociation constant for acids. Kc= [H][A]/[HA] Kw is the water dissociation constant. it is always 10^(-14) Buffer solutions strong acids fully disassociate into ions For every acid, there is a value of Ka which is constant the higher the Ka value, the stinger the acid (a perfect strong acid would have an infinite Ka value) there is also the extra value of pKa, which has the same relationship as with pH. The higher the value of pKa, the weaker the acid Kw=[OH][H] pKw=pH +pOH pKw=14 A buffer solution is a mixture of a weak acid and its conjugate base (which usually comes from a salt). this resists a change in pH when small amount of acid/alkail are added The Ph of buffer solutions can be worked out. But be aware that H+ does no longer equal A- when a acid is added, it increases [H+] which reacts with A-, and shift equilibrium to the rleft. When an alkali is added, it reacts with the few H+ ions to produce water. This reduces the concentration of H+ causing the equilibrium to shift to the right, to restore the lost H+ ions

Acids, Bases and Constants