Extreme112

My assignment asks me to "Write the Boolean equations for an 3 to 8 decoder." Now from what I think I understand, you'll get something like this http://en.wikipedia.org/wiki/Decoder#mediaviewer/File:Decoder_Example.svg. Are the minterms just the boolean equations? Because I don't really see how else to make boolean equations.

1) Na2S (aq) + Fe(NO3)2 (aq) ---> FeS (s) + 2 Na(NO3) (aq) Ksp = [Fe2+][s2-] Can someone explain why? 2) What is the Ksp for the salt Pb(IO3)2 if its solubility is 5.0 x 10-5 M? Answer is supposed to be 5.0x10-13. I also don't understand this.

Question: How many grams of sodium oxide are produced when 73.2g of sodium react completely with oxygen gas? Just want to confirm if my procedure/answer is correct. 4 Na + O2 ---> 2 Na2O ----- Balanced Equation So I would assume all I have to do is 1) get the moles of Na 2) divide my 2 to get the moles of Na2O 3) multiply by the molar mass of Na2O to get the grams of Na2O. Solution: 73g ÷ 23g/mol (molar mass Na) = 3.2 moles 3.2 moles ÷ 2 = 1.6 moles of Na2O 1.6 moles × 62 g/mol (molar mass of Na2O) = 98.7 Did I do my computations correctly?