Lab report
Data collection
Quantitative Data
Raw Data
Table 1: Table showing the mass of the amount of unknown acid X measured in grams (±0.001g)
Table 2: Table of reading of the burette initially filled with 25mL of 0.201moldm-3 sodium hydroxide (NaOH) to titrate 25mL (±0.03mL) of unknown acid X in mL (±0.05mL) after each titre.
Reading on the burette initially filled with 25mL of 0.201moldm-3 NaOH (±0.05mL)
First titre
21.3
Second titre
18.2
Third titre
15.2
Fourth titre
12.0
Qualitative data
Observations:
When dissolving the acid X in the water, most of it did not dissolve and become whitish foam sitting at the top of the solution.
When transferring the acid from the mortar to the flask by washing it with water, the low solubility of the acid made it hard and some of it was still stuck in the mortar and was not transferred into the flask.
When phenolphthalein was added to the unknown acid solution, the solution remained clear.
At first, when the NaOH base was added to the unknown acid solution, the solution where the base had dropped into changed into a pink colour which disappeared after swirling the flask containing the unknown acid, which returns to being clear.
However, after more NaOH base was added to the unknown acid solution, the solution eventually turned pink after swirling the flask.
Data processing:
As we did not refill the burette with NaOH each time after titrating the unknown acid, we need to calculate the difference of the volume before and after each titre. For example, the volume used in the first titre would be calculated by:
25-21.3=3.7 mL
Uncertainty:
(Uncertainty of the previous volume + uncertainty of volume after titration)
= (0.05+0.05)
=0.1mL
Calculating the rest of the titres in a similar fashion (previous volume-volume after titration) the following table of results is obtained:
Table 3: Table of the volume of 0.201moldm-3 sodium hydroxide (NaOH) used to titrate 25mL (±0.03mL) of unknown acid X in mL
Quantitative Data
Raw Data
Table 1: Table showing the mass of the amount of unknown acid X measured in grams (±0.001g)
Table 2: Table of reading of the burette initially filled with 25mL of 0.201moldm-3 sodium hydroxide (NaOH) to titrate 25mL (±0.03mL) of unknown acid X in mL (±0.05mL) after each titre.
Reading on the burette initially filled with 25mL of 0.201moldm-3 NaOH (±0.05mL)
First titre
21.3
Second titre
18.2
Third titre
15.2
Fourth titre
12.0
Qualitative data
Observations:
When dissolving the acid X in the water, most of it did not dissolve and become whitish foam sitting at the top of the solution.
When transferring the acid from the mortar to the flask by washing it with water, the low solubility of the acid made it hard and some of it was still stuck in the mortar and was not transferred into the flask.
When phenolphthalein was added to the unknown acid solution, the solution remained clear.
At first, when the NaOH base was added to the unknown acid solution, the solution where the base had dropped into changed into a pink colour which disappeared after swirling the flask containing the unknown acid, which returns to being clear.
However, after more NaOH base was added to the unknown acid solution, the solution eventually turned pink after swirling the flask.
Data processing:
As we did not refill the burette with NaOH each time after titrating the unknown acid, we need to calculate the difference of the volume before and after each titre. For example, the volume used in the first titre would be calculated by:
25-21.3=3.7 mL
Uncertainty:
(Uncertainty of the previous volume + uncertainty of volume after titration)
= (0.05+0.05)
=0.1mL
Calculating the rest of the titres in a similar fashion (previous volume-volume after titration) the following table of results is obtained:
Table 3: Table of the volume of 0.201moldm-3 sodium hydroxide (NaOH) used to titrate 25mL (±0.03mL) of unknown acid X in mL