22. (15 marks) The table below shows the elemental composition of a bitumen and its four fractions. Please calculate (1) Hydrogen-to-Carbon atomic ratio (HC), and density. (10 marks) (2) the fractions 1-4 correspond to the SARA fractions of the bitumen, please assign with the rationale. (5 marks) Elemental Bitumen Fraction 1 Fraction 2 Fraction 3 Fraction 4 composition (wt%) 84.26 83.93 86.05 85.93 80.55 H 9.07 7.58 11.73 13.40 6.94 0 1.22 0.42 0 0 1.50 3 N 0.43 4.97 1.21 5.66 0.30 1.92 0.61 0.06 1.80 8.73 S