Curve/LOBF (1 Viewer)

[bjw22]

When should we use a line of best fit and when should we use a curve of best fit - see 2005 hsc chem 22. I drew a curve and believe that it is more appropriate for this instance, but the marking criteria references a line and intersecting point. The conquering Chem solutions talk about two straight lines drawn and the point of intersection too - which seems a bit strange.

So when do we do a line, and when do we do a curve?

Also one other (stupid) question, why do we assume that 1g = 1mL, see hsc 2005 q 25a - got it right but don't understand?

 

[jazz519]

When should we use a line of best fit and when should we use a curve of best fit - see 2005 hsc chem 22. I drew a curve and believe that it is more appropriate for this instance, but the marking criteria references a line and intersecting point. The conquering Chem solutions talk about two straight lines drawn and the point of intersection too - which seems a bit strange.

So when do we do a line, and when do we do a curve?

Also one other (stupid) question, why do we assume that 1g = 1mL, see hsc 2005 q 25a - got it right but don't understand?

For that particular question I don't think either is really more correct. You are still gonna end up with the same type of curve in terms of the point that it goes flat, which is what you are probably using in the calculation after. On the most part, if the data looks linear use a line of best fit. if its curved or following some non-linear relationship then curve of best fit

We assume this because density of water in normal conditions is practically Density = 1.00g/ml so since density = mass/volume, then if density = 1, then 1=mass/volume, so mass = volume
giving you the 1g = 1mL (you can only assume this for whatever, other liquids it can change)

 

[bjw22]

That made so much sense thank you so much !!!!