Ban DHMO Article

1
Ban DHMO Article

• Is DHMO really water?
• What is the equation?
• Any properties/statements that you CANT tie to
  water?

2
Bond Strengths

• 1. Covalent Triple 3 electrons shared
• 2. Covalent Double 2 electrons shared
• 3. Covalent Single 1 electron shared
• 4. Ionic
• 5. Hydrogen
• 6. Van der Waals Forces

3
Chemical Reactions

• Bonds of atoms are broken and re-formed into new
  substances
• Reactions are written as chemical equations
  which show reactants and products
• All reactions in an organism Metabolism

What does balanced mean?
4
Chemical Reactions

• EXAMPLE
• 6CO2 6H2O ? C6H12O6 6O2
• This is the chemical equation for the reaction
  that occurs.

Notice the COEFFICENTS WHAT IS THEIR PURPOSE?
5
Acids and Bases

• Depending upon ions formed in solution substances
  are either acids or bases
• Acids Water ? H (H3O) ions
• Bases Water ? OH- ions
• Acids taste sour, corrosive
• Bases taste bitter, slippery

6
pH a measurement of hydrogen ions
Acids forms hydrogen (H) ions in water
(H3O) Bases forms hydroxide (OH-) ions in
water also called alkaline
Figure 2.10
7
pH Potential Hydrogen

• pondus hydrogenii
• Latin
• pouvoir hydrogène
• French
• hydrogen power, power of hydrogen or potential of
  hydrogen
• English
• What might H ions do?
• What might OH- ions do?

8
Acid and Base Strength

• The concentration of the acid/base does not
  determine how strong it is
• EX a REALLY concentrated acid can be WEAK
  harmless
• Acid and Base STRENGTH is based on how many H
  are given up (acids) or attracted to (bases) OH-
• Water cant equalize strong acids/bases
• Neutralization reaction acid base ? water
  salt (pH 7)
• NaOH (strong base) HCl (strong acid) ? NaCl
  (salt) H2O (water)

9
Acids in the Biology

• Ex HCl in stomach involved in digestion
• Acidic blood too much CO2 in body ? causes
  brain to speed up respiration (CO2 out and O2 in)
  ? blood more basic
• Lactic acid build up not enough O2 in muscles
  for aerobic respiration (soreness)
• Most food slightly acidic

10
Bases in Biology

• Neutralize stomach acids (antacids)
• Bile salts liver, pancreas emulsify lipids
  (fats) in body for digestion
• Many poisons are basicare foods?
• Many cleaners are basicwhy?

11
Buffers

• Buffers are weak acids and bases that can react
  with strong acids or bases to prevent sudden
  changes in pH.

12
Measuring pH

• There are several INDICATORS to measure pH
• pH paper
• litmus paper
• pH meter

13
Indicators

• The pH of a substance can be testing using the
  following indicators
• Ph paper gives the exact
• Litmus paper blue ? red acid, red ? blue
  base
• Phenolphthalein turns pink in the presence of a
  base, clear in an acid

14
Pre-LAB TIME

• What type of ions do acids make in solution?
• What type of ions do bases make in solutions?
• Water has the pH of ____.
• T/F- A substance with the pH of 9 would be
  considered an acid.
• T/F - Stomach Acid would likely have a pH of 1.

15
LAB TIME

• Show Ms. King your finished pre-lab Before
  getting materials!
• MUST wear goggles at ALL times!!!
• Aprons Optional
• Follow ALL Lab Safety rules!
• Change do not dump solutions!!!
• Lets measure the pH of some common substances
• Acid/Base HOUSEHOLD CHEMICALS LAB!