5.1.2 Titration Flashcards
What are the two names of the apparatus used in Titration
- Volumetric Pipette
- Burette
what is a volumetric pipette used for
measuring out 25 cm^3 very accurately
What is a Burette used for?
measure any volume to the nearest 0.05cm^3
Which apparatus does the known acid go in
Burette
Which apparatus does the unknown alkali go in
Conical flask
What is the setup of the conical flask
- using a volumetric pipette to measure out 25cm^3 into the conical flask
- add a few drops of either methyl orange or phenolphthalein indicator to the flask
- Fill burette with known acid and clamp it above the conical flask
why do you use
methyl orange or phenolphthalein and not a universal indicator
Because it doesn’t work as it changes the colour too gradual
What is the steps of titration
- Using the pipette measure 25.0cm^3 of unknown acid
- transfer into conical flask
- Add drops of methyl orange into conical flask
- place on white tile - Fill burette with known acid
- record initial volume - Whilst staring add in drops of Acid until reach end point
- yellow to red
5.Record final volume
- calculate difference ( final - initial reading)
- Repeat experiment until you reach concordant results
- within 0.20cm^3 of eachother
What does concordant results mean
Results within 0.20cm^3 with eachother
Why will the start colour be alkaline and the end colour be acid
Because the last drop of acid always has a tiny amount more than is needed to neutralise.
How do you work out titration results in mole calculations
- draw a grid with the information
- Look at the balancing numbers and work out a ratio
- Use the mole ratio form the equation to work out the moles of the substance
- with the calculated moles work out the concentration
- use the equation
(moles= conc x vol
