In Progress Lesson 1, Topic 1 In Progress Reduction reactions In a reduction reaction, one organic compound is reduced, sometimes by hydrogen gas and a catalyst and sometimes by an inorganic reagent.This means that the organic compound can either gain hydrogen or loose oxygenExample: Reduction of an alkene to an alkane by hydrogen gas and nickel catalyst This is a reduction reaction because two hydrogen’s have been gained.It is also an example of an addition reaction