In: Chemistry
Please explain...
In the titration of a weak acid HA with 0.100 M NaOH, the stoichiometric point is known to occur at a pH value of approximately 11. Which of the following indicators would be best to use to mark the endpoint of this titration?
a. an indicator with Ka = 10–13
b. an indicator with Ka = 10–14
c. an indicator with Ka = 10–10
d. an indicator with Ka = 10–8
e. an indicator with Ka = 10–11
An indicator HIn has Ka = 1 × 10–8. At pH = 6.0, what is the ratio HIn/In– ?
a. 1/100
b. 10/1
c. 1/1
d. 100/1
e. none of these