Use the following structures of amino acids to answer the questions below. note that the difference in the structures (the side chains) is highlighted by gray shading.

a student performed chromatography of the four amino acids and the results were shown in the chromatogram below. if an anion exchange column (column is positively charged) was used in a neutral buffer, assign each amino acid to the corresponding peak in the chromatogram.

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.