Question 3. Normal and Reverse Phase HPLC (Total: 10 marks) Liquid chromatography can be classified into two classes, the normal phase and reversed phase. 3.1. List the difference between the two LCs based on the chemical properties of the mobile and stationary phase. (3 marks) 3.2. List one example each of the R groups that can be used in normal and reversed phase LC. (2 marks) 3.3. Describe what is meant by eluotropic strength of the mobile phase. (2 marks) 3.4. The following analytes are present in a mixture: octane, propanoic acid, hexane, propanol. Give and explain the elution order of these analytes when they are separated using Reversed Phase LC