Instructions to follow Q1 • Solution is accepted in Handwritten format on a white A4 unruled sheet • Detailed and explained solution Avoid Al or plagiarism of any kind a. Molecular hydrogen, H2, undergoes dissociative chemical adsorption (chemisorption) on Ni- metal surfaces via an activated process. Experimentally, it is found that the enthalpy change for the chemical adsorption (AH) is -148 kJ mol −1 and the activation energy barrier, End is 12 kJ mol-¹ i. Explain what are meant by the following terms (one sentence for each): dissociative chemical adsorption activated adsorption process. (3 marks) ii. Describe how you can tell from a Lennard-Jones plot whether a process is activated or not. (2 marks) iii. Figure 3.1 shows a partially complete schematic potential energy profile (Lennard-Jones plot) to represent the chemical adsorption of H2(g) onto the Ni metal. Given that Ead = 12 kJ mol−¹, complete the potential energy profile by adding a second curve, with appropriate labels, to represent the physical adsorption of H2(g) onto Ni. Include arrows and labels on your sketch to indicate the values Ead, AHca, and Edes. (Note a copy of Figure 3.1 is provided in the Assessment area as a png file. You should paste a scanned image of your completed plot into your answer). potential energy (not to scale) HH !+ ! "Ni "Ni 2*Ni + H(g) + H(g) distance from surface Figure 3.1 A partially complete schematic potential-energy profile (Lennard-Jones plot) which shows the chemical adsorption of H2(g) onto the Ni metal. iv. Briefly explain how your plot accounts for the fact that adsorbed hydrogen atoms are formed on the Ni surface without prior dissociation of molecular hydrogen in the gas phase. (No more than 100 words). (4 marks) v. Write an expression for the activation energy for desorption (Edes) of hydrogen molecules from the Ni surface and calculate the value of Edes- (3 marks)