Acids and bases are fundamental compounds found everywhere in nature and in daily life. They are responsible for many natural processes and used in many products. An acid is a compound that increases the hydrogen ion (H+) concentration in water, donating protons. A base is a compound that increases the hydroxide ion (OH-) concentration in water, accepting protons. Common acids include hydrochloric acid and citric acid, while common bases include sodium hydroxide and ammonia. The pH scale measures how acidic or basic a solution is on a scale from 0 to 14. Acid-base reactions result in neutralization and salt formation.

1. Acids and Bases

2. Hawler
• Najmadin Hussen
• Erbil Medical institute

3. Where do we find Acids and Bases?
• They are compounds...
that are fundamental to the functioning of
our world. – we need them!
• They are essential to Life;
• They are responsible for many, many
processes in nature;
• They are important in may products and
processes we have come to expect in our daily
lives.
Continue Video to 3:15

4. • They are everywhere..
• In your food
• In your house
• EVEN IN YOU!!!!!

5. Acid
• The word acid comes from
the Latin acidus meaning
‘sour’ but in chemistry the
term acid has more specific
meaning.

6. What is an acid?
• An acid is a solution that has an excess of
H+ ions. It comes from the Latin word
acidus that means "sharp" or "sour".
• The more H+ ions, the more acidic the
solution.

7. Three Definitions of Acids and
Bases
• Svante Arrhenius (Swedish 1887)
• Bronsted- Lowry (Danish and
English 1923)
• Gilbert Lewis (American 1920’s)

8. Acids:
Arrhenius acid: Any substance that, when
dissolved in water, increases the concentration of
hydronium ion (H3O+).
Or an acid is a substance that increase the
concentration of hydrogen ions (H+) which are
carried as hydronium ions (H3O +), when dissolved
in water.

11.  Bronsted-Lowry acid: An acid
is a proton (hydrogen nucleus) donor.

12. Solvent – system definition:
An acid is a substance with increases the
concentration of solvonium cations such as
(H3O + ) in water, when dissolved in an auto
dissociating solvent.

13.  Lewis acid: An acid is an electron
pair acceptor.

15. Properties of an Acid
• pH less than 7
• Tastes Sour.
• Conduct Electricity.
• Corrosive, which means they
break down certain
substances. Many acids can
burn,skin, and paper.
• Some acids react strongly
with metals.
• Turns blue litmus paper to red
Picture from BBC Revision Bites

16. Uses of Acids
• Acetic Acid = Vinegar
• Citric Acid = lemons, limes,
& oranges.
• Ascorbic acid = Vitamin C
which your body needs to
function.
• Sulfuric acid is used in the
production of fertilizers,
steel, paints, and plastics.
• Car batteries.

17. Common Acids
• HCl- hydrochloric- stomach acid
• H2SO4- sulfuric acid - car batteries
• HNO3
– nitric acid - explosives
• HC2H3O2- acetic acid - vinegar
• H2CO3-carbonic acid – sodas
• H3PO4- phosphoric acid -flavourings

18. Common Acids
Vinegar
(acetic or ethanoic
acid)
Citric Acid

19. BASES

20. Common Bases
Ammonia

21. What is a base?
• A base is a solution that has an excess
of OH- ions.
• Another word for base is alkali.
• Bases are substances that can accept
hydrogen ions

22. Bases:
Arrhenius base: Any substance that, when
dissolved in water, increases the concentration of
hydroxide ion (OH-).
Bronsted-Lowery base: A proton acceptor.
Lewis acid: An electron donor.

23. Properties of a Base
• pH greater than 7
• Feel Slippery
• Taste Bitter
• Corrosive
• Can conduct electricity.
• Do not react with metals.
• Turns red litmus paper blue.

24. Uses of Bases
• Bases give soaps, ammonia,
and many other cleaning
products some of their useful
properties.
• The OH- ions interact strongly
with certain substances, such
as dirt and grease.
• Chalk and oven cleaner are
examples of familiar products
that contain bases.
• Your blood is a basic solution.

25. Common Bases
• NaOH- sodium hydroxide (LYE) soaps, drain cleaner
• Mg (OH)2 - magnesium hydroxide-antacids
• Al(OH)3-aluminum hydroxide-antacids, deodorants
• NH4OH-ammonium hydroxide- “ammonia”

26. Acids & Bases
STRONG vs WEAK
_ completely ionized _ partially ionized
_ strong electrolyte _ weak electrolyte
_ ionic/very polar bonds _ some covalent bonds
Strong Acids: Strong Bases:
HClO4 LiOH
H2SO4 NaOH
HI KOH
HBr Ca(OH)2
HCl Sr(OH)2
HNO3 Ba(OH)2

27. pH paper
• pH paper changes
color to indicate
a specific pH
value.

28. pH Scale
• pH is a measure of how acidic or basic a
solution is.
• The pH scale ranges from 0 to 14.
• Acidic solutions have pH values below 7
• A solution with a pH of 0 is very acidic.
• A solution with a pH of 7 is neutral.
• Pure water has a pH of 7.
• Basic solutions have pH values above 7.

29. pH Scale

30. pH
2 3 4 5 6 7 8 9 10 11 12
neutral @ 25oC
(H+) = (OH-)
distilled water
acidic
(H+) > (OH-)
basic or alkaline
(H+) < (OH-)
natural waters
pH = 6.5 - 8.5
normal rain (CO2)
pH = 5.3 – 5.7
acid rain (NOx, SOx)
pH of 4.2 - 4.4 in
Washington DC area
0-14 scale for the chemists
fish populations
drop off pH < 6 and
to zero pH < 5

31. Acid – Base Reactions
• A reaction between
an acid and a base is
called neutralization.
An acid-base mixture
is not as acidic or
basic as the
individual starting
solutions.

32. Acid – Base reactions
• Each salt listed in this
table can be formed by
the reaction between an
acid and a base.

33. Acid Rain
• Pollution in the air (sulfur dioxide,
carbon dioxide, nitrogen dioxide)
combines with water to form various
acids.
.

34. What is acid rain?
CO2 (g) + H2O  H2CO3  H+ + HCO3
-
Dissolved carbon dioxide lowers the pH
Atmospheric pollutants from combustion
NO, NO2 + H2O …  HNO3
SO2, SO3 + H2O …  H2SO4
both
strong
acids
pH < 5.3

35. What is a SALT?
• A salt is a neutral substance produced from the
reaction of an acid and a base.
• Composed of the negative ion of an acid and the
positive ion of a base.
• One of the products of a Neutralization Reaction
• Examples: KCl, MgSO4, Na3PO4

36. Digestion and pH
• Digestion-process by which foods are broken down
into simpler substances.
• Mechanical digestion-physical process in which food
is torn apart (mouth)
• Chemical digestion- chemical reactions in which large
molecules are broken down into smaller molecules.
(stomach and small intestines)

37. pH in the Digestive System
Mouth-pH around 7. Saliva contains amylase, an
enzyme which begins to break carbohydrates into
sugars.
• Stomach- pH around 2. Proteins are broken down into
amino acids by the enzyme pepsin.
• Small intestine-pH around 7. Most digestion ends.
Small molecules move to bloodstream toward cells
that use them

39. mouth
esophagus
stomach
small intestine
large intestine
Digestive system

40. Organic Chemistry:
Chemistry of compounds that contain carbon. Combine mainly with
hydrogen, oxygen, and nitrogen, Over 10 million compounds made
with these 4 elements. Form stable, covalent bonds with each
other. 95% of compounds contain carbon.
Where Organic compound found? Organic compounds naturally
exist in all living specie. Organic compounds (such as sugars or
chlorophyll etc.) are found in organic objects, such as people,
animals, plants, fungi, or bacteria.
What elements is found in organic compounds? All organic
compounds contain carbon. In addition they may have hydrogen,
oxygen, nitrogen, sulphur, halogens, phosphorus etc.

41. • Organic (Benzene)
– Low melting pts
– Low boiling pts
– Low solubility in water
– Highly flammable
– Nonconductive
– Covalent bonds
• Inorganic (NaCl)
– High melting pts
– High boiling pts
– Soluble in water
– Nonflammable
– Conductive
– Ionic bonds
Properties

42. Hydrocarbons:
Compounds containing only two elements, Carbon and hydrogen.
Properties:
1. Relatively nonpolar. (covalent bonds).
2. Insoluble in water. (like dissolves like).
3. Less volatile with increasing molar mass. (because of London
dispersion forces).

43. Types of hyrocarbones:
1. Alkane: single bonds; saturated (largest possible number of
hydrogens/carbon atom.
2. Alkene: one or more carbon-carbon double bond.
Unsaturated hydrocarbon.
3. Alkyne: one carbon-carbon triple bond. Unsaturated
hydrocarbon.
4. Aromatic: carbon atoms connected in a planar ring.
Unsaturated hydrocarbon.

44. Alkanes: [CnH2n+2]
• Saturated Hydrocarbons CnH2n+2.
• Called saturated because each carbon is bonded to four other
atoms.
• Only single bonds.
• Example: Methane, Ethane, Propane, …. Etc.
o Methane: CH4 major component of natural gas; home heating;
gas stoves; hot water heaters .
o Ethane: C2H6.
o Propane: C3H8 used for home cooking and heating; gas grills.
o Butane: C4H10 disposable lighters and fuel

46. Alkyl groups:
Alkyl groups are saturated hydrocarbons substituents with the
general formula CnH2n+1.

47. Alkenes: CnH2n
• End in -ene
• Unsaturated hydrocarbons
• Have a double bond (CH2=CH2)

48. Alkynes: CnH2n-2
• Carbon atoms share 3 pairs of electrons, forming a triple bond
• Alkynes have similar properties to those of alkanes and alkenes
• Naming is the same, except they end in -yne

49. Alcohols: R-O-H
Alcohols are one of the most important molecules in organic
chemistry. They can be prepared from many different types of
compounds and they can be converted into many different types of
compounds. Alcohols are molecules containing the hydroxy
functional group (-OH) that is bonded to a carbon atom of an alkyl or
substituted alkyl group. The hydroxy functional group strongly
contributes to the physical properties of alcohols.
Methanol (CH3OH)
• Often Called Wood Alcohol (Distilled From Wood)
• Prepared Now via Catalytic Hydrogenation
Reactions

50. Ethanol (CH3CH2OH)
• Made Through Fermentation of Sugars, in Alcoholic
Drinks
• Common Solvent in Organic Labs (Absolute
Ethanol)