Bell Work 41216 Get out foldable Get out

Bell Work 4/12/16 • Get out foldable • Get out Acid/Base Wkst #1 • Tape or glue today’s notes into the tab labeled “Strong Versus Weak Notes”

Acids & Bases Strong vs. Weak

Electrolytes • An electrolyte is a compound that dissociates in water into ions • These ions conduct electricity • All acids and bases are electrolytes • Not all acids and bases ionize completely

Ionization • The dissociation (breaking up) of an ionic compound into its ions. • Na. OH • H 2 SO 4 H 2 O Na+ +OH 2 H+ + SO 42 -

Strength • ability to ionize • The more easily the compound ionizes--the stronger the acid or base • In weak acids & bases, only partial ionization ocurs.

Strong Acids • Have a p. H less than 3 • There are 7 strong acids • HCl, HBr, HI, H 2 SO 4, HNO 3, HCl. O 4 Weak Acids • have a p. H between 3 & 7 • If an acid is not on the strong list, then it is a weak acid.

Strong Bases • Have a p. H greater than 11 • There are 8 strong bases • Li. OH, Na. OH, KOH, Rb. OH, Cs. OH, Ca(OH)2, Sr(OH)2, Ba(OH)2 Notice: These are all from Group 1 A and Group 2 A

Weak Bases • Have a p. H between 7 and 11 • If the base is not on the list of strong bases, then it is a weak base • Remember: Not all bases end in –OH. Example: NH 3

Writing Equations for Strong Acids and Bases • KOH • HNO 3 H 2 O K+ +OHH+ + NO 3 - (Notice the arrow going in one direction)

Writing Equations for Weak Acids and Bases • Fe(OH)2 • HC 2 H 3 O 2 H 2 O Fe 2+ + 2 OHH + + C 2 H 3 O 2 - (Notice the arrow going in two directions)

Phet Lab (On-Line Simulation) • • • Go to mrssoisson. weebly. com Go to Unit 12 and look for today’s date Click on “Link to Phet” Go to Intro and fill in table Next, go to socrative. com and take the quiz [Room Number: 4 f 6 c 8 fbc]