Name : Nikman Adli b. Nor Hashim (M04D)

Title : Determination of the Relative Molecular Mass of Amidosulphuric Acid.

Data collection :

Quantitative data :

Molarity of sodium hydroxide : 0.1033 M.Mass of amidosulphuric acid used : 2.5047 g.Volume of sodium hydroxide in burette : 50 cm³.Volume of amidosulphuric acid solution in conical flask : 25.0 cm³.

Table 2.0 : Volume of Sodium hydroxide in the experiment.

1 2 3 4

Initial burette reading (cm³) + 0.05cm³

0.00 0.00 0.00 0.00

Final burette reading (cm³) + 0.05cm³

25.50 25.20 25.00 25.00

Volume of HCl used (cm³) + 0.1cm³ 25.5 25.2 25.0 25.0

Qualitative data :

The colour indicator (methyl orange) in the amidosulphuric acid solution changes from red to orange. The hydrochloric acid used to neutralize the amidosulphuric acid solution did not change a lot between the four experiment I made.So, that means that the end point of the titration has been reached at 25.0 cm³ of sodium hydroxide.

Data processing:

The chemical equation: H2NSO3H + NaOH NaSO3NH2 + H2O.

The volume of hydrogen gas evolved: 16.10 cm³.

The number of moles of NaOH: = MV 1000

= (0.1033)(average volume of NaOH) 1000

= (0.1033)(25.175)1000

= 0.0026 mol

1 mol of amidosulphuric acid 1 mol of sodium hydroxide0.0026 mol of amidosulphuric acid 0.0026 mol of sodium hydroxide

The molarity of amidosulphuric acid:

M = mol x1000 V

Ma = 0.0026 mol x 1000 25 cm³

= 0.104 M.

The molarity of acid in 25 cm³ conical flask is similar to the molarity of acid in 250 cm³ volumetric flask. So, we can calculate the number of mole of the acid.

Mole = MV1000

Mole = (0.104 M)(250 cm³)1000

Mole = 0.026 mol.

The molar mass of amidosulphuric acid :

Molar mass = mass (g) Moles

= 2.5047 g0.026

= 96.3 g/mol.

Error analysis:

The actual molar mass of H2NSO3H = 97.10 g/mol.

The percentage of differences = |97.1 – 96.3| x 100 97.1

= 0.8 %.

Suggestion and limitations:

1) H2NSO3H was not completely dissolved.

2) A small quantity of H2NSO3H has been leave out in the beaker.

3) A small quantity of H2NSO3H has not completely dropped from the pipette.

4) Try to make more reading during titration (4 to 5 readings). 5)THE END POINT IS HARD TO DETERMINE.

Conclusion:

From the experiments, the molar mass of amidosulphuric acid that I got is 96.3 g/mol. From calculation, the percentage error of my experiment is 0.79 %.So, my results is getting comparable to the actual molar mass of amidosulphuric acid.