Is an odourless colourless gas producing oxygen and carbon dioxide when it burns a element or compound

In which reaction is precipitation occurring?

Anthracite is so hard and pure it is also referred to as a renewable resource metamorphic rock hot bituminous coal dirty fuel

The activation energy for the reaction no2(g)+co2(g)⟶no(g)+co(g) is ea = 300 kj/mol and the change in enthalpy for the reaction is δh = -100 kj/mol . what is the activation energy for the reverse reaction?