Lakhasly

Alternative Methods of finding composition of a mixture.
There are several ways to find the composition or concentration of a mixture of substances. A few of them are outlined below with their merits and demerits.

1. 
   

   Titration
   Titration (also known as volumetry or volumetric analysis) is a quantitative analytic method using a standard solution which reacts with the sample and shows a transition point at a defined ratio. Direct titration is the best-known form of titration.
   Advantages
   • High accuracy
   • Selective concentration determination in multi-component mixtures
   Limitations
   • Sample preparation necessary
   • Accuracy depends on mass solution
   • Destructive measurement
   • Chemical waste
   • Slow measurement cycle

   
   


2. 
   

   Chromatography
   Chromatography is an analytical method used for separation and concentration measurement of substances. The principle is based on molecular interaction between the dissolved analyte (mobile phase) and the environment (stationary phase). A stronger interaction with the stationary phase leads to a longer retention period and results in a separation of substances.
   Advantages
   • High accuracy
   • Selective concentration determination in multi-component mixtures
   Limitations
   • Sample preparation necessary.
   • Complex setup and experienced users necessary
   • Slow measurement cycle

   
   


3. 
   

   Refractometry
   Refractometry is a technique used to measure the refractive index of a substance. Using the refractive index, the concentration of a substance can be determined. This is because, from the meaning of refractive index, we can understand that the more particles or molecules, the slower light travels. Therefore, a water solution with no particles has a lower refractive index than a solution with some amount of sugar content inside which light travels more slowly.
   Advantages
   • Fast measurement
   • Low sample volume
   • High accuracy
   • No sample preparation
   • No moving parts in measuring instrument
   Disadvantages
   • Only binary and quasi-binary solutions accurately determinable
   From the above mentioned methods of composition determination, the best choice is the refractive index method (refractometry) because that method aligns with the objectives of the experiment, to analyze the composition of a mixture, to a high degree of accuracy.

   
   

The aim of the project is:
• Measure the refractive index using the refractometer.
• Plotting a graph of refractive index vs concentration to get a calibration curve.
• Using the curve to determine the composition of a unknown mixture through refractive index analysis.