Topic 12: Titration curves + pH

How do you measure pH?

• Universal indicator (paper/solution)

• pH meter (machine)

What are the pros and cons of the universal indicator?

• Pros: more convenient than pH meter

• Cons: Doesn’t work really well sometimes, colour might not match scale, very subjective

What are the pros and cons of the pH meter?

• Pros: More accurate as it gives pH to more sig figs than universal indicator

• Cons: Requires frequent calibration for reliable readings

How do you calibrate the pH meter?

Draw the titration curve for a strong acid + strong base reaction

Draw the titration curve for a strong acid + weak base reaction

Draw the titration curve for a weak acid + strong base reaction

Draw the titration curve for a weak acid + weak base reaction

What is the equivalence point?

point where thing in burette neutralises thing in flask

How do you calculate the equivalence point

What is the half-neutralisation point?

How do you use the half-neutralisation point to calculate the pH of the weak acid?

How do you choose an indicator for a titration curve?

When looking at the data table for a suitable indicator, what does pKin tell you?