Required practical: titration

Question 1

Step 1

Answer 1

Use a pipettes to transfer 25cm3 of sodium hydroxide solution into a conical flask (reduces risk of splashing)
Leave the solution to drip out instead of blowing

Question 2

Step 2

Answer 2

Add drops of phenolphthalein into the conical flask with the alkali

Question 3

Step 3

Answer 3

Place conical flask on white tile to see colour change more clearly

Question 4

Step 4

Answer 4

Fill a burette with sulphuric acid

Question 5

Step 5

Answer 5

Add acid to alkali until the solution is neutral
We do this by adding until we see a colour change, then add the acid drop by drop whilst mixing so we get an accurate measurement

Question 6

Step 6

Answer 6

Read the volume of the acid used on the burette

Ensure the meniscus sits at the line on the burette

Question 7

Step 7

Answer 7

Repeat several times until we have results within 0.1cm3 within each other
Calculate mean for final volume

Question 8

Why do we do this?

Answer 8

We have a volume of sodium hydroxide which we know’s concentration
So we can find volume of acid needed to neutralise it
Then work out acid’s concentration