chemical eqilibrium: indicators

Question 1

indicators are….

what can the dissociation be represented as?

Answer 1

-weak acids

Hln(aq) + H2O(l) => H3O+ (aq) +ln-(aq)

Question 2

what is the acid indicator dissociation constant represented as and what is the equation?

Answer 2

Kln

Kln= [H3O+][ln-]/[Hln]

Question 3

in aqueous solution the colour of an acid indicator is….

Answer 3

distinctly different from that of its conjugate base

Question 4

what ratio is the colour of the indicator determined by?

Answer 4

[Hln] to [ln-]

Question 5

give the equation for when the theoretical point at which colour change occurs

Answer 5

[H3O+] = Kln

Question 6

when is the colour change assumed to be distinguishable?

Answer 6

when is the colour change assumed to be distinguishable?

Question 7

what expression can be used to estimate the pH range over which a colour change occurs?

Answer 7

pH=pKln +/- 1

Question 8

what can suitable indicators be selected from?

Answer 8

-pH data (including titration curves)