unit 8 must knows duel

H2O pH is always... 7, could be acid (pH) or base (pOH)

how to increase/decrease buffering capacity

weak acid-strong base reaction

solution that is resistant to a small pH change, it has to contain a weak acid or base pared with its conjugate salt(Na+, H3O-, etc...) and it creates neutral compounds, keeping pH relatively stable

how do you calculate a buffer's pH

equivalence point

strong acid-weak base reaction

Kw =

within 1 pH of its pKa, up or down

maximum buffering capacity

strong acid strong base equivalence point

pH + pOH = 14 always!!

weak acid-strong base reaction HA(aq) + OH- --> A-(aq) + H2O(L) if weak acid is in excess --> a buffer --> Hendeson Hasselbalch equaiton if strong base is in excess, the moles of excess hydroxide ions is used for pH if acid and base are equimolar then the equilibrium concentr

strong acid-weak base reaction if weak base is in excess --> a buffer --> Hendeson Hasselbalch equaiton if strong acid is in excess, the moles of excess acid are used to determine pH if acid and base are equimolar then the equilibrium concentrations are used to determine pH

how to increase/decrease buffering capacity increasing/decreasing concentrations of buffer components, but keeping the ratios constant (if you don't it'll change the buffer capacity for either acid or base respectively)

equivalence point straight line up part of graph #miles of titrant = #moles of analyte concentration and volume of titrant is then used to determine concentration of analyte

Kw =

how do you calculate a buffer's pH pH = pKa + log [A-]/[HA] ---> acids pOH = pKb + log [BH+]/[B] ---> bases the conjugate salt is on top, and the bottom is either the base or the acid assume there is a limiting and excess reagent (because it will contain either a strong acid or base)

pH + pOH =

maximum buffering capacity

7, could be acid (pH) or base (pOH)

solution that is resistant to a small pH change, it has to contain a weak acid or base pared with its conjugate salt(Na+, H3O-, etc...) and it creates neutral compounds, keeping pH relatively stable

within 1 pH of its pKa, up or down

strong acid strong base equivalence point pH = 7 @ 25 C / 298 K

End this game?