Calibration curve is a method in analytical chemistry. It is used to determine or measure the concentration of a particular substance in a sample. This is done by comparing this sample of unknown concentration to a set of standard samples whose concentration is known.
Where is calibration curve in chemistry used?
The calibration curve in chemistry is used primarily to correct the problems of instrument calibration. The calibration curve in chemistry is used in conjunction with other methods. Other popular methods include that by which the standard sample may be mixed with the unknown, giving rise to an internal standard, which in turn may be described as a chemical substance that is added in a constant amount to samples used for chemical analysis.
The calibration curve in chemistry is a graph generated by experimental means. In this, the concentration of solution is mapped on the x-axis, while the observable variable is mapped on the y-axis.
How is the calibration curve constructed?
The calibration curve in chemistry gets constructed by the measurement ofcalibration standards. Calibration standards may be described as the concentration and absorbance of numerous prepared solutions. After plotting the curve, calibration curve in chemistry helps determine the concentration of the unknown solution when it is placed on the curve. This determination is done depending on its absorbance or other such observable variables.
Calibration curve in chemistry and spectrophotometry
Chemical solutions have the ability for absorbing different amounts of light based on the levels at which they are concentrated. The absorbance of a solution can be measured using a laboratory instrument called a spectrophotometer, in a process known as spectrophotometry.
Spectrophotometry plays a role in the calibration curve in chemistry because it helps to determine the concentration of an unknown solution. Spectrophotometry is immensely useful in arriving at a calibration curve in chemistry.
Calibration curve in chemistry for measuring various substances
If a scientist wants to know the level of say, chlorine in tap water, all that she has to do is to plot a calibration curve in chemistry of the sample. Many standard solutions of chlorine of varying concentration can be placed on the spectrophotometer, which shows a different absorbance for each of these.
Further, these experimentally determined absorbance values are mapped on a graph in relation to the known concentration of each calibration standard, after which a set of points is created, leading to the use of the calibration curve in chemistry to analyzing the concentration of chlorine.