Systematic Errors in Volumetric Titration

[chimpy400]

We're conducting a practical tommorow on the ammonium concentration in lawn fertiliser through back titration.

It is a common question throughout our SACs to ask about Systematic Errors in Volumetric titration and I am lacking ideas. (apparently equipment can't be used, e.g. calibration error.)

ty

[Somye]

I'm not sure if this is a systematic error, but you could talk about errors which arise if you use wrong methods of cleaning the apparatus

ie. if burette not washed properly then conc. decreases. hence more vol needed hence leads to higher calculated values

or if pipette not cleaned properly than lower mol of ammonium and then lower solution required to neutralise and therefore lower calculated values

[Shenz0r]

You could possibly talk about your primary standard reacting with the atmosphere if it's an effluent substance (meaning that it absorbs moisture from the atmosphere, like sodium carbonate), which will mean that your weighed mass of the primary standard will be incorrect every time you conduct the experiment, and hence the concentration of your standard solution will be inaccurate.