titration of sodium hydroxide with tetraoxosulphate4 acid.
To explain the titration of sodium hydroxide (NaOH) with tetraoxosulphate(IV) acid (H2SO4), we will need the balanced chemical equation for the reaction:
2 NaOH + H2SO4 → Na2SO4 + 2 H2O
In this titration, the sodium hydroxide solution is usually the titrant (known concentration) while the tetraoxosulphate(IV) acid solution is the analyte (unknown concentration). The purpose of the titration is to determine the concentration of the analyte (H2SO4) by reacting it with a known volume and concentration of the titrant (NaOH) until the reaction is stoichiometrically complete.
Here's a step-by-step explanation of how to perform the titration:
1. Prepare the solutions:
a. Measure a known volume of the tetraoxosulphate(IV) acid solution into a flask using a pipette.
b. Add a few drops of an appropriate indicator to the acid solution. Phenolphthalein is commonly used, which is colorless in acidic solutions and pink in basic solutions.
c. Pour a known volume of the sodium hydroxide solution into a burette. Make sure to record the initial volume reading.
2. Perform the titration:
a. Slowly add the sodium hydroxide solution from the burette to the flask containing the tetraoxosulphate(IV) acid solution while swirling the flask.
b. Watch for the indicator's color change. In this case, phenolphthalein will turn pink when all the tetraoxosulphate(IV) acid has reacted and the solution has become basic.
c. Continue adding the sodium hydroxide solution drop by drop, right after the color change, until it remains permanent (i.e., the pink color persists for about 30 seconds).
d. Record the final volume reading on the burette.
3. Calculate the concentration:
a. Determine the volume of the titrant (NaOH) used to neutralize the acid solution. This can be obtained by subtracting the initial burette reading from the final reading.
b. Use the balanced equation to find the ratio of moles between the analyte (H2SO4) and the titrant (NaOH). In this case, the ratio is 2:1.
c. Calculate the molarity (concentration) of the analyte using the volume of the titrant and its known concentration.
d. Adjust the result, if necessary, based on any dilution or known factors.
It's important to note that while the balanced equation assumes a simple stoichiometry, practical titrations may require additional considerations, such as the presence of water or the need for multiple indicators. Additionally, laboratory safety precautions should be followed during the procedure.