This is regarding to the super long post.

Dr.Bob, did you actually check all of my answers?

Do you want me to make several small posts now?

By the way I don't understand how #1 is wrong!!!!!

I checked only #1. You were to calculate concns of Sn and NO3^- and I showed by calculations. Check those against yours. My answers are 0.00909 for Sn and 4*that for NO3^-. Your numbers are 10x smaller than those (for each one).