# Titration to analyse a solution of dilute sulphuric acid, and calculating the concentration of acid that it contains.

Ifrah Naz

Titration to analyse a solution of dilute sulphuric acid, and

calculating the concentration of acid that it contains.

Introduction/Aim:

In this coursework my aim is to find out how much acid there is in a solution. I am going to use the technique of titration to analyse a solution of dilute sulphuric acid, and calculate the concentration of acid that it contains. This concentration is considerably greater than the concentration of acid in “acid rain”, but the same method of analysis could be used to determine accurate values of PH for “acid rain” samples.

I must find out the accurate concentration of acid, which is thought to have a concentration between 0.05 and 0.15 mol dm-3.

The purpose of this experiment is to obtain an accurate concentration of sulphuric acid, which is found in solution. We are told that the sulphuric acid to be used has a concentration between 0.05 and 0.15 mol dm, but the task is to clarify the exact concentration using the method of titration.

The indicators that I can use are either phenolphthalein or methyl orange this is because according to the titration curve for strong acid with strong base, the pH range for methyl orange (3.1-4.4) and the pH range of phenolphthalein (8.3-10.0) is very near to the equivalence point, therefore we can use either phenolphthalein or methyl orange as the indicator when sodium hydroxide solution is titrated with standard sulphric acid solution. However by using methyl orange I am likely to get more precise results, so therefore I will be using methyl orange as the indicator.

This is the equation for the titration:

H2SO4 (aq) + Na2CO3 (aq) -- Na2SO4 (aq) + CO2 (g) + H2O(l)

Apparatus to be used:

The apparatus that are to be used for this method of titration to work out the amount of acid that there is present in a solution are:

• 1 pipette filler – to transfer acid rain.
• Dropping Pipette
• 1 conical flask – 100 cm3
• Beakers 100 cm3
• Methyl orange indicator
• 1 burette
• Small filter funnel
• Wash bottle and distilled water
• Mortar and pestle
• Sodium hydroxide
• Acid rain
• Funnel
• White Tile
• Clamp and clamp stand
• Goggles – need to be worn at all times for eye protection.

Safety: Risk Assessment:

Method:

Preparing my stock solution:

• Weigh the empty bottle
• Leave the bottle on scale and make sure the scale reads 00.00
• Using a spatula weigh 6.1g of sodium carbonate in the weighing bottle
• Put about 100cm3 of distilled water into a 250cm3 beaker.
• Carefully pour the sodium carbonate from the weighing bottle into the beaker.
• Wash out the bottle with distilled water 3 times to ensure all the sodium carbonate comes out of the bottle.
• Use the mixing rod to break all the crystals.
• Add more distilled water if necessary. (remember there should be no more than 250cm3 ...