The concentration of $H_2C_2O_4$ in the rhubarb extract is closest to
A - VCE - SSCE Chemistry - Question 17 - 2018 - Paper 1
Question 17
The concentration of $H_2C_2O_4$ in the rhubarb extract is closest to
A. 5.43 x 10^-3 M
B. 5.00 x 10^-2 M
C. 2.17 x 10^-2 M
D. 7.40 x 10^-4 M
Worked Solution & Example Answer:The concentration of $H_2C_2O_4$ in the rhubarb extract is closest to
A - VCE - SSCE Chemistry - Question 17 - 2018 - Paper 1
Step 1
Step 1 - Titration Setup
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
In this step, a 20.00 mL aliquot of the rhubarb extract was placed in a 200 mL conical flask. It is important to accurately measure the volume to ensure proper concentration calculations.
Step 2
Step 2 - Preparing the Titrant
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The burette was filled with acidified 0.2000 M KMnO4 solution. Ensuring the solution is acidified is crucial as it allows for complete reaction with the oxalic acid.
Step 3
Step 3 - Performing the Titration
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The titration process involved gradually adding the KMnO4 solution to the rhubarb extract until a permanent change in colour, indicating the endpoint, was observed. The volume of KMnO4 used in the titration should be carefully noted.
Step 4
Step 4 - Repeating the Experiment
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Finally, the titration was repeated until three concordant results were obtained. The average of these concordant titrations, which was found to be 21.7 mL, can now be used to calculate the concentration of oxalic acid in the extract.
