Weak, Strong and Nonelectrolytes Woohoo Chemistry!!!

Agenda -Attendance - Hand back all stuff -Hand out Cheat sheets -Review: Go over homework questions. -Solubility chart -Notes on Weak and Strong electrolytes with equations. -Demo with different types of solutions and electricity -Give Vocabulary Words -Review Videos Links -Go over the test -Question period (including go over some and hand in your questions that you created)

Review: Homework questions Vultures are a type of bird that is able to eat rotting meat because of extremely strong gastric juices. These gastric juices are actually aqueous solutions. What is an aqueous solution? When too many restaurants open in the same neighborhood, you may hear people say that the market for restaurants is saturated. Explain what is meant by this statement and relate it to saturated solutions. What is a saturated solution? Unsaturated solution? Supersaturated solution? What the difference between electrolyte and nonelectrolyte? Come up with two different questions that could be asked on an exam and the answers to those questions

Solubility Chart How do I read this thing? Negative ion first Positive ion second

Electrolytes Electrolyte- dissolves in water, breaks up into ions and conducts an electric current. Nonelectrolyte- dissolves in water, does not break up into ions, therefore not conducting electricity NaCl Example in water Vs Sugar in water Table sugar dissolves in water because when a sucrose molecule breaks from the sugar crystal, it is immediately surrounded by water molecules. The sucrose has hydroxyl groups that have a slight negative charge. The positive charge of the oxygen found in the water molecule binds with the sugar. As the hydration shell forms around the sucrose molecule, the molecule is shielded from other sugar molecules so the sugar crystal does not reform.

Strong and Weak Electrolytes Strong Electrolyte: A substance that is completely ionized in solution. Ex. Strong acids, Strong bases and most salts. Weak Electrolyte: A substance that only party ionizes in solution. Example Ethanol and Chloroform.

Weak and Strong Electrolytes H20 (l)  H + (aq) + OH- (aq) NaCl (s)  Na+ (aq) + Cl- (aq) C12H22O11 (s)  C12H22O11 (aq) HCl (l)  H + (aq) + Cl- (aq) CH3COOH  CH3COO- (aq) + H + (aq) CuSO4  Cu 2+ (aq) + SO42- (aq) NH3  (g) → NH4+ (aq) not going to try this one

Demo H20 (l) --> H + (aq) + OH- (aq) NaCl (s) --> Na+ (aq) + Cl- (aq) C12H22O11 (s)  C12H22O11 (aq) HCl (l)  H (aq) + Cl (aq) CH3COOH  CH3COO (aq) + H (aq) CuSO4  Cu (aq) + SO4 (aq) H+ + NH3 → NH4+ Salt (strong), Sugar C12H22O11(non elec), Copper (II) sulfate (strong), HCl (strong), ethanol(nonelectrolyte), Acetic acid and ammonium (weak).

Strong Acids HCl - hydrochloric acid HBr - hydrobromic acid HI - hydroiodic acid (also known as hydriodic acid) HNO3 - nitric acid H2SO4 - sulfuric acid HClO4 - perchloric acid HClO3- chloric acid

Strong Bases LiOH lithium hydroxide NaOH sodium hydroxide KOH potassium hydroxide RbOH rubidium hydroxide CsOH cesium hydroxide Ca(OH)2 calcium hydroxide Sr(OH)2 strontium hydroxide Ba(OH)2 barium hydroxide

Vocabulary mixture / compound define both terms and list the key differences between a mixture and a compound. give an example of each homogeneous / heterogeneous mixtures solutions are which type of mixture? Colloids / Suspensions / Solutions / Tyndall effect aqueous solutions solute / solvent define both terms. Give at least one specific examples of solutions involving: gases dissolved in other gases; liquids dissolved in other liquids; solids dissolved in liquids. Identify the solute and solvent in each case soluble / insoluble solubility unsaturated / saturated / supersaturated how can you prepare a supersatured solution? electrolyte / nonelectrolyte (or electrolytic solution / nonelectrolytic solution) What causes the one type of solution to conduct electricity, while the other one does not? Polar / Nonpolar / Ionic Define each. What’s the difference between each? Which solutes will dissolve in which solvents?

Videos Having trouble with the difference between suspensions and colloids watch some videos: http://www.youtube.com/watch?v=Ti0QroYDta8  Colloids suspension solution http://www.youtube.com/watch?v=AlrqitFCNLw  suspension colloid demos http://www.youtube.com/watch?v=bn1-Zgcpp_4  Colloids Strong Weak and Nonelectrolytes Video with demos if your having trouble: http://www.youtube.com/watch?v=Pxegf2KKiuc

What's on the exam/ Question Period