Part D: Thinking & Inquiry: (10 marks) 15. Explain three ways how a chemist can maximize the yield of Caois, in the following reaction. (6 marks) CaCO3(s) + heat CaO + CO2@ 16. The chemical responsible for the brown color of photochemical smog is nitrogen dioxide. Nitrogen dioxide is an unstable molecule, that exists in the following equilibrium with colourless dinitrogen tetraoxide: (5 marks) 2NO2(e) = N20 AH =-57.20 kJ/mol a. A scientist takes an air sample from downtown Toronto during the winter at 0C and finds the following equilibrium concentrations: [N204) = 2.0 x 107, [NO2) = 6.23 x 105. What is the key for this reaction at 0C? (1) b. During the summer, the same scientist collects another sample at 25C and finds the following equilibrium concentrations: [N204) = 3.5 x 10, [NO2] = 6.59 x 104. What is the key for this reaction at 25C? (1) c. What do your results from (a) and (b) suggest about when smog would be the worst? What explains the difference in the equilibrium between summer and winter? (2)