Launch: 1/22   Grab your binder and immediately take a seat!

  Place launch paper and practice questions (Tuesday 1/19) on your desk.

  Tuesday’s Exit Slip Data:

  Today’s Objective: I can define a Brønsted-Lowry acid and base.

96%

Launch 1/21

1. Which of the following is true about acids? a.  they taste bitter b.  they turn litmus paper blue c.  they have a pH of greater than 7

d.  they taste sour and turn litmus paper red

Launch 1/21 2.  Baking soda is an example of an

a.  acid because it turns litmus paper red b.  base because it has a pH of about 8.5

c.  acid because it turns litmus paper blue d.  base because it tastes similar to lemons

Launch 1/21 3.  Which of the following solutions would have the

highest acidity? a.  pH 11 b.  pH 9 c.  pH 5

d.  pH 2

Launch 1/21 4.  Which of the following explains why Kool-aid

powder dissolves in water? a.  The Kool-aid powder is cold and therefore has a high

solubility. b.  The random motion of the solvent molecules causes

collisions with the solute molecules and dissolving occurs.

c.  The solute has strong intermolecular attractions and is therefore easily dissolved.

d.  The concentration of the solute is higher than the concentration of the solvent and dissolving occurs.

Announcements   Missing work is due today

  Check board for your name

  Quiz tomorrow!   Short quiz – 15 MC

  Lab questions due tomorrow!

  Unit #6 exam moved to Thursday 1/28

January Calendar

What are strong acids/bases?

Mr. Heffner 1/22/10

What are strong acids/bases?   Strong acids/bases…

  fully dissociate in solution

“break up”

HCl H+ + Cl–

Hydrogen ion

Chloride ion

NaOH Na+ + OH–

Sodium ion

Hydroxide ion HCl

H+ H+

H+ H+ H+

H+ H+ Cl-

Cl-

Cl-

Cl-

Cl-

Cl-

NaOH

Na+ Na+

Na+ Na+ Na+

Na+ Na+ OH-

OH-

OH-

OH-

OH-

OH-

all broken

up

What are weak acids/bases?   Weak acids/bases…

  only partially dissociate in solution

“break up”

HF H+ + F–

HF

HF H+

HF HF H+

H+ HF F-

F-

F-

F-

F-

F-

partially broken

up

Summary

Hydrogen ion HCl

H+ H+

H+ H+ H+

H+ H+ Cl-

Cl-

Cl-

Cl-

Cl-

Cl-

HCl H+ + Cl–

Strong acids/bases

  fully dissociate

Weak acids/bases

  partially dissociate

HF H+ + F–

HF

HF H+

HF HF H+

H+ HF F-

F-

F-

F-

F-

F-

Video Summary

What are strong acids/bases?   What happens if you mix a strong acid and a strong

base?

  strong acid + strong base = water + salt   Neutralization

HCl + NaOH ?

H+ + Cl- Na+ + OH- + ? H2O + NaCl

water salt

Practice Questions   Practice question worksheet

Exit Slip 1.  Which of the following are properties of acids?

a.  they taste bitter and turn litmus paper blue b.  they have a pH of less than 7 and turn litmus paper red

c.  they have a pH of greater than 7 and taste sour d.  they usually feel slippery like soap

Exit Slip 2.  The Bronsted-Lowry definition of a base is

a.  a molecule that loses an electron b.  a molecule that has a pH of greater than 7

c.  a molecule that donates hydrogen ions d.  a molecule that accepts hydrogen ions

Exit Slip 3.  In the equation, H2O + HI H3O+ + I-, which

reactant molecule acts as the acid? a.  H2O b.  HI c.  H3O+

d.  I-

Exit Slip 4.  In the equation, H2PO4

- + H2O H3PO4 + OH-, which reactant molecule acts as the base?

a.  H3PO4 b.  OH- c.  H2PO4

-

d.  H2O

Exit Slip 5.  Why could SO4

2- not act as a Bronsted-Lowry acid? a.  because it can donate O2- ions to solution b.  because it has no H+ ions to donate to solution

c.  because it cannot accept any H+ ions d.  because it has a pH of 6

Homework   Finish practice questions