ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: a/b on March 06, 2011, 05:52:00 pm
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A prac on a back titration of fertilizer to find it's nitrogen content is going to be our SAC. I'm still confused with random and systematic errors though.. what would count as a systematic error? Measuring 1.31g fertilizer instead of 1.30g? Or the fact that the fertilizer never completely dissolved into a solution?
Thanks :)
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Systematic errors usually occur at the very beginning, for instance, measuring 1.31g of fertilizer instead of 1.30g as you said.
What this means, is that all subsequent working out would use 1.31g and be incorrect.
However, if you have shown correct use of formulas and balanced chemical equations, you would still receive marks. :)
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Oh ok thanks :) and when we have to talk about overcoming these errors, how would I go about it with that example?
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Systematic errors usually occur at the very beginning, for instance, measuring 1.31g of fertilizer instead of 1.30g as you said.
What this means, is that all subsequent working out would use 1.31g and be incorrect.
However, if you have shown correct use of formulas and balanced chemical equations, you would still receive marks. :)
Just to add to that,
System errors is one that is not affected by randomness and is all about accuracy. Like measuring your fertilizer, setting up your burette, pipette etc.
Random Errors occurs for instance, through titration and its all about precision. Like titrating to find your end point, sometimes, you go over, but if you have tried your best, then it was unpreventable. Random errors is one where, even though you have done everything by the book (systematic), the errors that arises cannot be prevented, however only reduced through concise and precise work .
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Thankyou :) I have the SAC tmr so it'll definitely help!