What is the molar masses for C8H10N2O4

Is this a single replacement reaction or there is no

Consider the four elements above. which one of these elements will combine with oxygen in a 1: 1 ratio?

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?