Q.When two properties of a system are mathematically related to each other, the relation can be deduced by a. Working out mean deviation b. Plotting a graph c. Calculating relative error d. all the above three

Analytical chemistry often needs to find the mathematical relationship between two or more measured properties, and the standard tool for this is plotting the data on a graph. Simply joining scattered experimental points in sequence produces a meaningless zig-zag pattern caused by ordinary experimental error, so instead a single smooth 'average' curve is drawn through the general run of the points (in the classic temperature-vs-volume example for a fixed mass of gas, this average curve turns out to be a straight line, from which $V \propto T$ can be inferred). Whether a drawn curve is a genuinely good fit is judged in an even-handed, quantitative way: a perpendicular is dropped from every data …