if a solution is undergoing a reaction where co2 is being used as a reactant, what color is the phenol red-containing solution shifting toward?

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).

H tricky one let me think and get back to u