Announcements “Limiting Reactants” lab write-up due tomorrow at start of discussion. Online HW 5 (Type I) due Monday 10/21 and (Type II) due Wednesday 10/23 by 7:00pm.

From Tuesday… Assume you have 5.00 g of Mg and 10.0 g of CO2 available. You allow them to react. Prove that mass has been conserved.

Clicker #1 When lead(II) nitrate and potassium iodide are mixed, what precipitate will form? Pb(NO3)2(aq) + KI(aq) → A) KNO3 B) KI C) Pb(NO3)2 D) PbI2 E) No precipitate will form. Solubility Rules Most nitrate salts are soluble. Most salts of sodium, potassium, and ammonium cations are soluble. Most chloride and iodide salts are soluble. Exceptions: Ag+ and Pb2+. Most sulfate salts are soluble. Exceptions: Ca2+, Ba2+, and Pb2+. Most hydroxide salts are only slightly soluble. Soluble ones are: Na+, K+, and Ca2+. Most sulfide, carbonate, and phosphate salts are only slightly soluble.

Example #1 What volume of KI solution do you need to completely react with Pb(NO3)2? What is the mass of solid produced? What are the concentrations of the ions left in solution after the reaction is complete?

Clicker #2 What ions are left in solution after the reaction is complete? I. Pb2+ II. NO3– III. K+ IV. I– A) II and III B) I and IV C) II, III and IV D) I, II, III and IV E) No ions are left in solution after the reaction is complete.

Example #2 Same reaction (and volumes) but different amounts: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) 0.0100 mol 0.0500 mol What is the mass of solid produced? What are the concentrations of the ions left in solution after the reaction is complete?

Clicker #3 What ions are left in solution after the reaction is complete? I. Pb2+ II. NO3– III. K+ IV. I– A) II and III B) I and IV C) II, III and IV D) I, II, III and IV E) No ions are left in solution after the reaction is complete.