Topic 4 Titrations

Question 1

What are titrations

Answer 1

A method of analysing the concentrations of a solution

Question 2

What do Titrations allow you to do

Answer 2

Allow you to find out exactly how much acid is needed to neutralise quantity of alkali

Question 3

Titrations practical steps 1-2 want or find how much acid is needed to neutralise a quantity of alkali

Answer 3

1) Using a pipette and a pipette filler add a to set volume of alkali to a conical flask
Add two or three drops of indicator
2) Use a funnel to fill a burette with an acid if known concenration. Record the initial volume of the acid in the burette

Question 4

Titrations practical steps 3-5

Answer 4

3) using the burette Add the acid to the alkali a bit at a time, giving the conical flask a regular swirl Go especially slowly when Do you think the endpoint(colour change) is about to be reached
4) indicator changes colour when all the alkali has been neutralised
5) Record the final volume of acid in the burette and use it along with the initial reading to calculate the volume of acid used to neutralise the alkali

Question 5

How do you increase the accuracy of your titrations

Answer 5

Need to take several consistent readings
The first titration you should do should be a rough titration to get an approximate idea where the solution changes colour (end point)
Turn repeat the whole thing a few times making sure you get pretty much the same answer each time
Calculate the mean of your results ignoring any anomalous result

Question 6

What is the universal indicator used for

Answer 6

Estimate the pH of a solution because it contains a variety of colours
each colour indicates a narrow range of pH values

Question 7

What colours are the universal indicator are acidic

Answer 7

Dark red
red
orange
yellow

Question 8

What colour is a universal indicator are alkali

Answer 8

Light blue
dark blue
purple

Question 9

What should you want to see on an indicator during titrations

Answer 9

Sudden colour change (end point)

Question 10

What type of indicators are used for titrations

Answer 10

A single indicator such as
litmus (Blue in alkalis red in acid)
Phenolphthalein (Pink in alkalis and colourless in acids)
Methyl orange (Yellow and alkalis Red in acids)