This is a report about Aldehydes. The content of this slideshow are as follows: What is an aldehyde, How to name aldehydes with IUPAC Nomenclature and Common Names, The Physical Properties of Aldehydes, and the examples of aldehyde and its uses. The main objective of this report is to widen the knowledge of the readers/learners concerning of the stated topic so that they can further understand the concept of aldehydes. Report made by: Students of Sogod National High School STEM 9-Newton Kyla Krystelle Salva Krishia Belle Cambalon Marycris Felicilda

1. Aldehydes

2. Carbonyl Group
- is a carbon atom double-
bonded to an oxygen atom.

3. Aldehydes
-is a carbonyl-containing organic
compound in which the carbonyl
carbon atom has at least one hydrogen
atom directly attached to it.
- Linear notations: -CHO and -RCHO

4. •An aldehyde functional group can be bonded
to only one carbon atom because three of the
four bonds from an aldehyde carbonyl carbon
must go to oxygen and hydrogen.
•Always found at the end
•Cyclic aldehydes are not possible

5. Nomenclature for Aldehydes
Aldehydes are named using the suffix –al. The
suffix –al denotes an aldehyde.
The IUPAC rules are:
Rule 1: Select as the parent carbon chain the
longest chain that includes the carbon atom of
the carbonyl group

6. •Rule 2: Name the parent chain by changing the
–e ending of the corresponding alkane name to
–al.
•Rule 3: Number the parent chain by assigning
the number 1 to the carbonyl carbon atom of
the aldehyde group. The number 1, however,
does not become part of the name.

7. •Rule 4: Determine the identity and
location of any substituents, and append
this information to the front of the parent
chain name.
•Rule 5: When an aldehyde functional
group is attached to a carbon ring, name
the ring and add the suffix –carbaldehyde.

8. •The common name for aldehydes are one
word.
•The aldehyde common names illustrate a
second method for counting from one to
four in organic chemistry language: form-
, acet- , propion- , butyr- , benz- ,

9. ISOMERISM FOR ALDEHYDES
Constitutional isomers exist for aldehydes.
Ex:
Aldehyde
Skeletal isomers: CH3 ─ CH2 ─ CH2 ─ C ─ H
═
O
CH3 ─ CH ─ C ─ H
CH3
═
O
═

10. SELECTED COMMON ALDEHYDES
Formaldehyde
-an irritating gas when in room
temperature and pressure
-bubbling through water produces formalin
-reacts with water, producing methylene
glycol

11. CH3─OH ───── H─C─H + H2
═
O
Ag Catalyst
600°C ─ 700°C
Formaldehyde is manufactured on a
large scale by oxidation of methanol

12. Formalin
• Used for preserving biological specimens
• Has pungent odor
• Most widely used preservative chemical in
embalming fluids
• Reacts with protein molecules that leads to
“hardening” of the protein.
H ─ C ─ H + H ─ O ─ H ───── HO ─ CH2 ─ OH
═
O

13. ACETALDEHYDE
• widespread, naturally occurring, colorless
and flammable liquid with a suffocating smell
• Used for acetic acids, perfumes, dyes and
drugs, as a flavoring agent and as an
intermediate in the metabolism of alcohol
• reasonably anticipated to be a human
carcinogen
• Somewhat more toxic than ethanol

14. CHEMICAL FORMULA OF ACETALDEHYDE

15. VANILLIN
• Primary component of vanilla
bean
• used as a flavoring agent in
foods, beverages, and
pharmaceuticals
• First commercial synthesis of
vanillin began with eugenol

16. STRUCTURAL FORMULA OF VANILLIN
(Methoxybenzaldehyde)

17. PHYSICAL PROPERTIES OF ALDEHYDE
•Straight-chain saturated aldehydes are liquids,
and the higher aldehydes are solid
•Higher boiling point than alkanes
•Has lower boiling point than alcohols
•Soluble in both organic solvents and water if it has
less than 6 carbon atoms

18. •Having 6 or more carbon atoms, compounds
are soluble in organic solvents and not in
water
•Low-molecular-mass have pungent,
penetrating, unpleasant odors
•Higher-molecular-mass (above C8) are more
fragrant

19. Type of
Compound
Compound Structure Molecular
Mass
Boiling
Point
(8°C)
Alkane
Aldehyde
Alcohol
Ethane
Methanal
Methanol
CH3─CH3
H─CHO
CH3─OH
30
30
32
─ 89
─ 21
65
Alkane
Aldehyde
Alcohol
Propane
Ethanal
Ethanol
CH3─CH2─CH3
CH3─CHO
CH3─CH2─OH
44
44
46
─ 42
20
78
Alkane
Aldehyde
Alcohol
Butane
Propanal
1-propanol
CH3─CH2─CH2─CH3
CH3─CH2─CHO
CH3─CH3─CH2─OH
58
58
60
─ 1
49
97

20. Water Solubility
Number of
Carbon Atoms
Aldehyde Water Solubility
of Aldehyde
1 Methanal Infinite
2 Ethanal Infinite
3 Propanal 16
4 Butanal 7
5 Pentanal 4
6 Hexanal 1
7 Heptanal 0.1
8 octanal insoluble

21. Oxidation of Aldehydes
Oxidation is an increase in the number of C-O
bonds

22. •The aldehyde gains an oxygen atom
•Aldehydes must be protected from air
•When prepared from oxidation of primary alcohol, it
is usually removed from the reaction mixture
immediately to prevent it from being further oxidized
to carboxylic acid
•Oxidizing agent potassium dichromate (K2Cr2O7) is
often used for aldehyde oxidation reactions

23. •Oxidation of an aldehyde involves breaking a
carbon-hydrogen bond
•The Tollens Test or silver mirror test, involves
a solution that contains silver nitrate (AgNO3)
and ammonia (NH3) in water
•When added to an aldehyde, Ag+ ion is
reduced to silver metal, forming a silver
mirror.

24. R ─ C ─ H + Ag+ ─────── R ─ C ─ OH + Ag
NH3, H2O
heat
═
O
═
Aldehyde Carboxylic
Acid
O
Silver
metal

25. Reduction of Aldehyde
• Aldehydes are easily reduced by hydrogen gas
(H2) in the presence of a catalyst (Ni, Pt, or Cr)
to form alcohols.
• Produces primary alcohols
Aldehyde ──────── primary alcohol
Reduction

26. Aldehyde reduction to produce alcohols is the “opposite”
of the oxidation of alcohols to produce aldehydes.
Primary
Alcohol
Aldehyde
Oxidation
Reduction

27. REACTION OF ALDEHYDES
Aldehyde reacts with alcohols to form hemiacetals and
acetals. Reaction with one molecule of alcohol produces a
hemiacetal, which is then converted to an acetal by reaction
with a second alcohol molecule.
Aldehyde + Alcohol ─────── hemiacetal
Acid
Catalyst
Hemiacetal + Alcohol ─────── acetal
Acid
Catalyst

28. H. Stephen Stoker. (2011). Aldehydes and Ketones. General,
Organic and Biological Chemistry Sixth Edition. (pp. 469-487).
BROOKS/COLE CENGAGE Learning.

29. THANK
YOU! 😃