4. What mass of solid product is produced when 15mL of a 0.25M Pb(NO3)2 is reacted with excess NaCl?

Ineed with this also i hope you understand it

The answer is nitrogen-containing bases

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).