"if the volume is kept constant, and nothing is added to the reaction mixture, what happens to the partial pressure of nitrogen during the course of the reaction? "

The correct answer is:   bri hope this answer was ! : )

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).