2. Catalyst 1.Balance the following chemical reaction: C 6 H 12 O 6 + O 2  H 2 O + CO 2 2. Determine the molar mass (formula weight) of the following compounds: a. H 2 SO 4 b. Pb(NO 3 ) 2 End

3. Hair Dryer in a Bath Tub

4. Justify – TPS What chemical properties lead to the explosive reaction of dropping a hair dryer in water?

5. Lecture 3.1 – Electrolytes and Net Ionic Equations

6. Lecture 3.1 – Net Ionic Equations and Electrolytes LT 3.1 – I can identify a compound as being a strong, weak, or non – electrolyte. LT 3.2 – I can translate a chemical reaction into a net ionic equation that contains only the ions/molecules that participate in the chemical reaction.

7. Electrolytes vs. Nonelectrolytes When you dissolve compounds in water, sometimes they dissociate and sometimes they do not. Electrolyte – Any compound that breaks into ions when in solution and can conduct electricity Nonelectrolyte – Any compound that does not form ions when in solution and cannot conduct electricity.

8. Ionic Compounds are Electrolytes When a ionic compound is dissolved in water, it breaks apart into positive and negative ions. Polar water molecule breaks up the ionic crystal

9. Covalent Compounds are Nonelectrolytes When a ionic compound is dissolved in water, it cannot be broken apart. Polar water molecule cannot break apart these compounds because there are no ions

10. Strong vs. Weak Electrolytes Electrolytes can be characterized as being either strong or week based on the amount they dissociate. Strong Electrolytes – Compounds that completely dissociate in water. Weak Electrolytes – Compounds that almost dissociate completely in water

14. Class Example Is the following compound an electrolyte or a nonelectrolyte If it is an electrolyte is is strong or weak? KCl

15. Table Talk Is the following compound an electrolyte or a nonelectrolyte If it is an electrolyte is is strong or weak? C 6 H 12 O 6

16. Net Ionic Equations Oftentimes we see chemical equations written as this: Pb(NO 3 ) 2 (aq) + 2KI (aq)  PbI 2 (s) + 2KNO 3 The electrolytes that are in aqueous solutions can be written as their ions: Pb 2+ + 2NO 3 2- + 2K + +2I -  PbI 2 + 2K + +2NO 3 - Molecular Equation Complete Ionic Equation

17. Net Ionic Equations Many of the ions are present on both sides, so they do not participate in the chemical reaction and can be canceled out. Pb 2+ + 2NO 3 2- + 2K + +2I -  PbI 2 + 2K + +2NO 3 - Pb 2+ (aq) + 2I - (aq)  PbI 2 (s) Net Ionic Equation

18. Class Example Write the net ionic equation for the following reaction: Mg(NO 3 ) 2 (aq) + Na 2 CO 3 (aq)  MgCO 3 (s) + 2 NaNO 3 (aq)

19. Table Talk Write the net ionic equation for the following reaction: SrBr 2 (aq) + K 2 SO 4 (aq)  SrSO 4 (s) + 2 KBr (aq)

20. Investigate and Check

21. Exit Ticket 1.Are the following compounds electrolytes or non-electrolytes? If it is an electrolyte, then is it strong or weak? a. KBr b. CO 2 c. CH 3 COOH (a weak acid) 1.Write the net ionic equation for the following reaction: Na 2 CO 3 (aq) + Co(NO 3 ) 2 (aq)  2NaNO 3 (aq) + CoCO 3 (s)

23. Closing Time Read sections 4.1 and 4.2 in textbook Complete Homework 3.1 Net Ionic Equations for class Thursday/Friday Lab 5 Pre-Lab due at the start of the next class