Quiz on unit 8 must knows

#1 Which of the following definitions matches the term?

pH + pOH =

14 always!! 7, could be acid (pH) or base (pOH) pH = 7 @ 25 C / 298 K pH = pKa

#2 Which of the following terms matches the definition?

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

what is a buffer maximum buffering capacity equivalence point strong acid-weak base reaction

#3 Which of the following terms matches the definition?

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)

strong acid-weak base reaction Kw = pH + pOH = how to increase/decrease buffering capacity

#4 Which of the following definitions matches the term?

weak acid-strong 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 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 1.0 x 10^-14 at 25 C or 298 K 7, could be acid (pH) or base (pOH)

#5 Which of the following definitions matches the term?

maximum buffering capacity

pH = pKa 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 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 pH = pKa

#6 Determine if the following combination is true or false.

strong acid strong base equivalence point

pH = pKa

True

False

#7 Determine if the following combination is true or false.

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)

True

False

#8 Determine if the following combination is true or false.

in what range are buffers effective

within 1 pH of its pKa, up or down

True

False

#9 Determine if the following combination is true or false.

what is a buffer

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

True

False

#10 Determine if the following combination is true or false.

H2O pH is always...

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

True

False

Section 1: Multiple Choice questions

pH + pOH =

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

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)

weak acid-strong base reaction

maximum buffering capacity

Section 2: True/false questions

strong acid strong base equivalence point

pH = pKa

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)

in what range are buffers effective

within 1 pH of its pKa, up or down

what is a buffer

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

H2O pH is always...

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

Triple-checked your answers?

Quiz menu