Practical investigations
Read our general notes on Risk Assessment
I'm writing my very detailed plan out for an acid-base titration investigation to find the concentration of acid. How would I justify choosing a 250 cm3 volume of the alkali of known concentration?
Ulex replies
It depends a little on what equipment is available - check to see what volumetric flasks you actually have.
It also depends on what pipette size you are intending to use. The alkali should normally be in the pipette rather than the burette because, if the burette has a glass tap, the alkali tends to attack the glass, causing the tap to stick. If the tap is made of plastic such as Teflon, it doesn't matter. If the pipette is going to be 25 cm3 you could do up to 10 titrations with the 250 cm3 - probably more than you would need to do. If using a 10 cm3 pipette, you could do 25 titrations. This is surely excessive. Make 100 cm3 of solution instead.
Always carry out a risk assessment and check with your teacher before starting any practical work.
Risk assessment
Before attempting any practical work based on the advice and suggestions on this website, you must do the following. Identify any hazards, assess the risks from these hazards, and then decide appropriate control measures to reduce the risks. You must have these approved by those in authority in your school or college laboratory. Do not rely on what is said on this website.
For further guidance see our tutorial on Risk Assessment.
back to Practical investigations
Rate this page or react
Share your views on this page, 3 ratings so far
, rated at 
updated: 24 March 2006
