Titration

Question 1

What is the purpose of titrations?

Answer 1

Titrations allow us to determine the exact volume of acid required to neutralise a given volume of alkali (vice Versa)

Question 2

How do we know when we’ve reached the end point of the reaction?

Answer 2

When the indicator changes colour to show that the alkali has been neutralised

Question 3

Why is it difficult to tell the exact pH of a solution using universal indicator?

Answer 3

The colour change between pHs is gradual and so the exact pH is difficult to identify

Question 4

Why are single indicators more suitable for titrations?

Answer 4

Because they show a SUDDEN COLOUR change at the point of neutralisation

Question 5

What are THREE examples of single indicators?

Answer 5

• litmus
• methyl orange
• phenolphthalein

Question 6

What colour does the single indicator LITMUS turn in
- acidic solutions (pH below 7)
- neutral solutions (pH around 7)
- alkaline solutions (pH above 7)
(3 POINTS!!)

Answer 6

• acidic (pH below 7) litmus turns RED
• neutral (pH close to 7) litmus REMAINS PURPLE
• alkaline (pH above 7) litmus turns BLUE

Question 7

What is the colour of methyl orange at pH2?

Answer 7

Red

Question 8

What colour does methyl orange turn at pH7?

Answer 8

Yellow

Question 9

What colour is phenolphthalein at pH 7?

Answer 9

Colourless

Question 10

What is the colour of phenolphthalein at pH10?

Answer 10

Pink

Question 11

How do we know if a result is concordant?

Answer 11

If it’s not within 0.10 cm cubed of the other results