Reactions Of Acids- Titrations

Question 1

What does a titration measure?

Answer 1

A titration can be used to measure the volumes of acid and alkali that react wih
each other.

Question 2

What is a pipette used for?

Answer 2

A pipette is used to measure a fixed volume of a solution.

Question 3

what is a burette used for?

Answer 3

A burette is used to obtain an accurate measurements of the volume of the
solution added.

Question 4

An acid / base indicator with a _____ end point eg p______________, is used.

Answer 4

An acid / base indicator with a sharp end point eg phenolphthalein, is used.

Question 5

state the stages carried out for a titration

Answer 5

1. use a pipette to transfer 25cm^3 of sodium hydroxide solution into a flask
2. add 5 drops of an indicator such as phenolphthalein to the alkali in the conical flask
3. place the flask onto a white tile so we can clearly see the color change
4. fill a burette with sulphuric acid
5. add acid until solution is neutral, once you see a color change add the acid drop by drop until solution is neutral, remember to swirl solution
6. read the volume of acid added from the burette

Question 6

what is the color change of phenolphthalein?

Answer 6

pink - colorless

Question 7

how do you take a reading from the burette

Answer 7

by going down to level your eye with the burette and taking a reading from the bottom of the meniscus

Question 8

how many times do you repeat a titration

Answer 8

several times until you get two readings within 0.1 cm^3 - we then take a mean if these

Question 9

talk through how you would do a titration calculation

Answer 9

1. write c= m= v= under both the acid and the alkali
2. enter the information given - convert volumes to dm^3 (divide by 1000)
3. work out the other information

Question 10

how do you work out the moles
(not mass/ mr)

Answer 10

concentration x volume

Question 11

how do you work out the concentration

Answer 11

number of moles / volume