titrations

Question 1

what is a titration?

Answer 1

an analytical method used to determine the concentration of a solution of a known volume by gradually adding a solution of a known concentration to it until a neutralisation occurs

Question 2

what is the analyte?

Answer 2

a solution with an unknown volume and concentration

measured with a pipette and placed into a conical flask

Question 3

what is the standard solution

Answer 3

has a known concentration, it is filled into a burette and gradually added to the analyte

Question 4

what is the indicator, why is it used?

Answer 4

phenolphthalein- pink to colourless when adding acid to alkali

methyl orange , yellow - orange red when adding acid to alkali

to visually determine when neutralisation has occurred. this causes a colour change at the end point.

Question 5

how can we determine the concentration of the analyte.

Answer 5

by calculating the volume of the standard solution required to reach the end point, you can determine the concentration

Question 6

what are the steps for carrying out a titration?

Answer 6

1. Measure the analyte into a conical flask using a pipette, and add an indicator.
2. Fill the burette with the standard solution and note the initial reading.
3. Gradually add the standard solution to the flask, swirling to mix, until you approximately reach the point of neutralisation.
4. Refill the burette and repeat steps 2 and 3 to get an approximate idea of where neutralisation occurs.
5. Conduct a precise titration by adding the standard solution slowly to identify the exact end point. Record the final burette reading, also known as the titre volume.
6. Perform the titration multiple times to obtain concordant results, which are titre volumes that differ by no more than 0.10 cm3.
7. Calculate the mean titre volume using the concordant results.

Question 7

how do you prepare a standard solution?

Answer 7

1. Weighing a precise mass of solute using a balance.
2. Dissolving the weighed solute in distilled water in a beaker.
3. Transferring the solution to a volumetric flask of a specific volume.
4. Rinsing the beaker several times with distilled water and adding the rinsings to the volumetric flask.
5. Diluting the solution to the mark on the volumetric flask with a pipette.
6. inverting the flask several times to ensure thorough mixing of the solution.

Question 8

what is the formula for concentration
g dm-3

Answer 8

conc= mass of solute / volume in dm3

Question 9

what is the calculation for concentration in moles dm-3 ?

Answer 9

conc = moles / volume