Titration Technique Flashcards
What is a standard solution
A solution of accurately known concentration
Why are they prepared
To be used in titrations as the reactant of known mass
Why is a volumetric flask used to make a standard solution instead of a beaker or clonical flask
A volumetric flask is a more accurate piece of glassware than a beaker or clonical flask
The concentration of the solution you will make depends on the number you are given for con and volumes
Cons of
0.1
0.05
0.2
0.15
Are used for 100cm3
Conc of 0.02 = 250 cm
How can the mass of a substance be measured
Using an accurate balance
Measuring of using a mass balance
•Place the peice of apparatus required on the balance and tare
Or
Add the required mass of the substance to the piece of apparatus required
Stage 1 of standard solution
•Dissolve the substance in a small volume of deionised water
•make the solution up to the graduation point with deionised water, stopper and invert to mix evenly
•transfer solution into volumetric flask with washings
Filling up barrette
•Rinse the burette with the solution it is to be filled with
• fill above the scale with solution
• Remove the filter funnel and open the tap to drain the solution until the bottom of the meniscus sits on the zero mark and no air bubbles are present
Feeling a pippette
•Rinse the pipette with the solution it is to be filled with
•fill pipette above graduation mark with solution
• allow liquid to drop down until the bottom of the meniscus sits on the zero mark and no air bubbles are present.
Type of pippetes
Volumetric and Graduated
Graduated pippetes
Can measure any whole volume up to their maximum volume
I.e pippetes measure any whole volume between 0 & 30
Volume pipette
Have no scale on the side of them and can only measure the set volume the are designed for
25cm only
Burette
Used to accurately and gradually at small volumes of substance to a reaction
Brett will allow you to add a decimal point to volume as it has a 0.1 cm³ graduation mark on its scale
