Launch: 1/19   Grab your binder and immediately take a seat!

  Place launch paper on your desk.

  Friday’s Quiz Data:

  Today’s Objective: I can describe the properties of acids and bases.

90%

Launch: 1/19   Grab your binder and immediately take a seat!

  Place launch paper on your desk.

  Friday’s Quiz Data:

  Today’s Objective: I can describe the properties of acids and bases.

82%

Launch: 1/19   Grab your binder and immediately take a seat!

  Place launch paper on your desk.

  Friday’s Quiz Data:

  Today’s Objective: I can describe the properties of acids and bases.

80%

Launch: 1/19   Grab your binder and immediately take a seat!

  Place launch paper on your desk.

  Friday’s Quiz Data:

  Today’s Objective: I can describe the properties of acids and bases.

87%

Announcements   The semester ends tomorrow

  Missing work is due today

  Quiz tomorrow!

  Lab due tomorrow!

  Unit #6 exam moved to Thursday 1/28

January Calendar

What are acids & bases? – Part II

Mr. Heffner 1/21/10

Review: What are acids and bases?   Solutions can be classified as…

Acids   pH < 7   taste sour

  Ex: lemon juice   burn skin   turn litmus paper red

Bases   pH > 7   taste bitter

  Ex: soap   feel slippery   turn litmus paper blue

“pH scale”

What are acids and bases?   The Brønsted-Lowry definition:

  Acids donate hydrogen ions   Bases accept hydrogen ions

  Hydrogen ions are positively-charged hydrogen atoms

  Symbol =

charged atoms

H+

Example 1.  In the following reaction, identify the acid and the

base.

  HF loses (donates) = acid

  H2O gains (accepts) = base

HF + H2O F- + H3O+ loses an

H+ forms gains an

H+ forms

Example 2.  In the following reaction, identify the acid and the

base.

  HSO4- gains (accepts) = base

  H2O loses (donates) = acid

HSO4- + H2O H2SO4

- + OH-

gains an H+

forms loses an H+

forms

Example 3.  In the following reaction, identify the acid and the

base.

  HCl loses (donates) = acid

  H2O gains (accepts) = base

HCl + H2O Cl- + H3O+ loses an

H+ forms gains an

H+ forms

Example 4.  In the following reaction, identify the acid and the

base.

  H3PO4 loses (donates) = acid

  H2O gains (accetps) = acid

H3PO4 + H2O H2PO4- + H3O+

loses an H+

forms gains an H+

forms

Whiteboards   Work in pairs

  Trade-off marker every question

  Partner without the marker should be checking work at each step!

  You have 60 seconds to solve the question   Show all of your work!   Don’t forget units!

  Lift board only when prompted

H2O + HF H3O+ + F-

In the above equation, which reactant molecule is the acid?

HI + H2O H3O+ + I-

In the above equation, which reactant molecule is the base?

HSO4- + H2O H2SO4 + OH-

In the above equation, which reactant molecule is the base?

H2PO4- + H2O HPO4

2- + H3O+ In the above equation, which reactant

molecule is the acid?

H2O + NaHCO3- NaCO3

2- + H3O+ In the above equation, which reactant

molecule is the acid?

OH- + HSO4- SO4

2- + H2O In the above equation, which reactant

molecule is the base?

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 and H+ ions d.  pH 2

Homework   Finish practice questions