ATAR Notes: Forum

VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: VCE_2012 on June 10, 2012, 10:22:44 pm

Title: Please check my respose for :2011 VCAA/sectionB/Q3/c/ii
Post by: VCE_2012 on June 10, 2012, 10:22:44 pm
"The sample of the espresso coffee should be diluted enough so it's peak area is contained within the range of the calibration curve."

I'm a bit edgy because it's usually "diluted enough so its concentration" but in this case there was peak area and that is what I used. So would I still get a mark?
Title: Re: Please check my respose for :2011 VCAA/sectionB/Q3/c/ii
Post by: ligands on June 10, 2012, 10:25:30 pm
I'd you didn't mention the peak area you don't get a mark
Title: Re: Please check my respose for :2011 VCAA/sectionB/Q3/c/ii
Post by: charmanderp on June 10, 2012, 10:35:29 pm
You'd have to either state the minimum dilution factor or say 'dilute so that the peak area of the expresso peak fits within the range accounted for by the calibration curve.'
Title: Re: Please check my respose for :2011 VCAA/sectionB/Q3/c/ii
Post by: t35t on June 10, 2012, 10:47:54 pm
"The sample of the espresso coffee should be diluted enough so it's peak area is contained within the range of the calibration curve."

I'm a bit edgy because it's usually "diluted enough so its concentration" but in this case there was peak area and that is what I used. So would I still get a mark?

I think it's right. The essence of the question was mentioning that it had to be diluted so that it would fit the calibration curve no? Plus, the marking scheme specified "dilution" AND "dilution by a factor of..." - the reason why both these points is mentioned was because some students wrote "by a dilution factor <12", in which case it would still not fit the calibration curve. Just like the marking scheme in biology, sometimes *not* overcomplicating it reduces the chances of making a mistake.... and isn't what you said essentially the same as what the examiner report outlined?