This link Optimum Mixture Ratio shows a range of mixture ratios for Lox-Kerosene of 2.1 to 2.45. Its not clear to me where in this range is the stochiometric case. Some Russian designs are higher (RD-180 being ~2.7) while the Merlin 1D is 2.34 and the F1 was 2.27 (all according to Comparison_of_orbital_rocket_engines).
Question. In the relatively fuel rich cases is there unburned kerosene and what happens to it after leaving the engine?
My main interest is the environmental impact. I'm also interested, as an aside, to understand whether the main contribution of unburned kerosene is from the main exhaust or is more a feature of gas generator engines that dump the turbine exhaust separately.
EDIT inspired by comment: This link Liquid fuel / Oxygen proportions hints that stochiometric could be in the range 2.58-2.77.