Standardisation of sulphuric acid using standard sodium hydroxide solution.
Introduction
You will use a standard solution to find the concentration of dilute sulphuric acid by titration.
This process is known as standardising the sulphuric acid.
The reaction between sodium hydroxide and sulphuric acid is:
2NaOH(aq) + H2SO4(aq) Na2SO4 (aq) + 2H2O(l)
1.
Apparatus
Goggles, 100cm3 beaker, 250cm3 beaker, 250cm3 conical flask,
25cm3 bulb pipette, Pipette filler, Burette, Burette stand and holder,
Plastic filter funnel, white tile, teat pipette
Access to:
Standard sodium hydroxide solution (0.1M), dilute sulphuric acid to standardise
methyl orange indicator solution.
Method
1. Transfer a 25cm3 aliquot (portion) of your sodium hydroxide solution to a 250cm3 conical flask. Add a few drops of methyl orange indicator solution.
2. Titrate with the sulphuric acid (in burette). The end-point of the titration is when the solution just changes from yellow/orange to red. Note the titre.
4. Repeat steps 1 - 3 until concordance (i.e. until the readings are the same or within 0.1cm3).
5. Tabulate your titrations as before.
Results
|Burette reagent | |
|Conical flask reagent | |
|Indicator | |
| | Run 1 | Run 2 | Run 3 | Run 4 | Run 5 |
|Final volume (cm3) | | | |...