How many formula units are in 6.12 kg of lithium nitride

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).

It's b, limestone.i gotchu, b.

Because they need to be tested more in real world condition and hydrogen gas or fuel is really expensive compared to present diesel and gasoline. hopefully this : )