Straight Lines/Standard Curves

TOC

The “plug and chug” method 

It is as easy as determining the slope of the line from the standard curve and using it in the formula: OD=ec.

So, using this method,

the kids' cordial had an OD of 0.8. 

the slope of the line is 5

0.8 = 5c so

c=0.8/5 = 16 % (v/v)

...rather than the 25% (v/v) recommended by the manufacturer.  This is almost the identical result as when we read it off the graph.