2. An aqueous solution of MgF2 has a boiling point 100.330C. Assuming the idealized van't Hoff factor (i), what is the concentration of MgF2 in solution. Kb=0.512C/m1. [5 marks] 3. Determine the rate law and the value of k for the following reaction using the initial rate data provided: [8 marks] S2O8(aq)+31(aq)2SO42(g)+13(aq) 4. The overall second order reaction of chlorine radical and hydrogen gas to give HCl and hydrogen radical is shown below. Cl(gl)+H2(g)HCl(g)+H(g) An Archenius plot of lnk (the rate constant) versus 1/T (in K1 ) gives a slope of 2767.2K and a y intercept of 25.112. a) What is the value activation energy (Ea)? Three significant figures will suffice. [2 marks] b) What is the value of the pre-exponential frequency factor (A)? Three significant figures will suffice. [3 marks] c) Assuming that 'overall second order' means 1st order in Cl(g) and 1st order in H2(g), is the plot of reaction rate versus [H2(g)] linear or not? Give a very brief reason for your answer [1 mark] 5. Consider a reaction with two steps whose 1st step is the slow (RDS) step. A+BCCD+E a) If the overall reaction is slightly exothermic, sketch a diagram showing the energy changes associated with the reaction. You should label your starting materials products, intermediates, activation energies, transition states and reaction enthalpy. [7 marks] b) Describe the effect of a catalyst on..... [2 marks] i) the activation energy (EB) of a reaction. ii) the overall enthalpy (Hrm) of a reaction