org chem funk groups Flashcards
Describe the era of organic chemistry
-95% of all known compounds are made of carbon.
-Organic chemistry influences all aspects of our lives:
Clothing, materials (polymers), oil, medicine, our bodies!
-50% of all chemists are organic chemists
-Structures, mechanisms, synthesis
What is organic chemistry?
-Modern organic chemistry is the chemistry of carbon containing compounds (Verbindung)
What is the history of organic chemistry?
- 1780: Organic compounds are very complex and can only be obtained from living sources (vitalism)
- 1784: Lavoisier observed that organic compounds are made of carbon, hydrogen and oxygen.
- 1828: Wohler obtained an organic compound (urea) from an inorganic compound (ammonium cyanate).
- 1860: Avogadro proved the emprical and molecular formulas hypothesis.
What are isomers?
-Isomers: Different compounds having the same molecular formula
Ex: etyl alcohol and dimetyl ether
In which shape does methane occur?
-tetrahedral (109.5°)
Which bondings are used to fulfill the octet rule?
- Ionic bonding: giving electrons; force of attraction btw oppositely charged ions.
- Covalent bonding: sharing electrons
What are ions/ Electronegativity?
- Ion: charged particles formed when electron(s) are gained or lost
- Electronegativity: degree of ability of an atom to attract electrons.
What can you say about the ionic bonds?
- Ionic compounds are solids with high melting points.
- They are dissolved in polar solvents (Lösungsmittel) such as water.
- Their solutions usually conduct electricity.
What can you say about the covalent bonds?
- Bonds formed by atoms with same or similar electronegativities.
- Atoms aim to achieve noble gas configuration.
- Products formed are called molecules.
- > Molecules do not have net electrical charges; Molecules are neutral.
- Molecules are shown by their Lewis structures.
How to calculate formal charge?
- FC=V-N-B/2
- V is the number of valence electrons of the neutral atom in isolation
- N is the number of non-bonding valence electrons on this atom in the molecule; and
- B is the total number of electrons shared in bonds with other atoms in the molecule
What is the sum of formal charge equal to?+ calculate the formal charge of ammonium and nitrate ions
-to the total charge of a molecule or an ion
-ammonium= NH4+
N=5-0-4=1
H=1-0-1=0
-nitrate ions= NO3-
O=6-6-1=-1
N=5-0-4=1
O=6-4-2=0
What is the most important property of carbon? What do the functional groups determine and how are they determined?
- ability to form covalent bonds with other carbon atoms (and also with H, O, S, N)
- they determine physical and chemical properties
- their presence is determined by using infrared spectroscopy
What are hydrocarbons? What are Alkane, Alkene, Alkyne, Aromat
Which of the named above is called saturated?
- Compounds containing only carbon and hydrogen
- Alkanes: single bonds btw carbon atoms
- Alkenes: double bonds btw carbon atoms
- Alkynes: triple bonds btw carbon atoms
- Aromatic: special ring structure
- akenes(containing max possible number of bonds)
General facts about alkanes
- are saturated
- main source: natural gas and petroleum
- Small molecule alkanes (methane to butane) are gas at room temperature
- Methanogens: organisms which produce CH4 from CO2 and H2
Give some facts about ethene and propene (Alkene)
- are the simplest
- ethene (or ethylene) =
- natural plant hormone, promotes growth
- ethanol, ethylene oxide and polyethylene are produced from ethene
- propene=
- very important industrial chemicals such as polypropylene and acetone are produced from propene
Where can ethyne (acetylene) be found and where is it used? (alkyne)
- They are found in nature and can be synthesized in laboratory
- They are used as fuel in lamps and in reducing flame
- They are also found in the atmospheres of the satellites of our solar system
- ethinyl estradiol is used in contraceptives (Verhütungsmittel) (similar to estrogen)
Describe the aromatic hydrocarbon
- best example is benzene
- proposed by August Kekule (is wrong (resonance is right))
- ring structure, unsaturated
Most chemical reactions involve? Describe for alkene, alkyne, alkane
- functional groups
- they determine chemical and physical properties
- alkene: carbon-carbon double bond
- alkyne: carbon-carbon triple bond
- alkane: no func. group!!! C-C and C-H bonds are very unreactive!
How are alkyl groups obtained and what is the R symbol standing for?
- They are obtained by the removal of a terminal hydrogen atom from an alkane
- «R» is used as a general symbol to show any alkyl group
What are phenyl groups and benzyl groups composed of?
- When the benzene ring is attached to other atoms in a molecule (-R-), it is called a «phenyl group»
- «Benzyl group» is composed of a phenyl group and –CH2-
How are alkyl halides/ halo alkanes formed?
-They are formed when a hydrogen atom of an alkane is replaced by a halogen atom (such as fluorine, chlorine, bromine or iodine)
ex: CH3Cl and CH3CH2Br
-They are classified as primary, secondary or tertiary alkyl halides.
(-This classification is done according to the carbon atom which the halogen is bonded to)
What are alcohols?
- The simplest member of alcohols is methyl alcohol or methanol (CH3OH)
- Their functional group is the hydroxyl (OH) group
ex: ethyl alcohol or ethanol (CH3CH2OH) - hydroxy derivatives of alkanes
- alkyl derivatives of water
How is the classification of alcohols
- They are classified in 3 groups: primary, secondary and tertiary alcohols
- This classification is done according to the substitution level of the carbon atom to which the hydroxyl atom is bonded
Give the general formula of ethers, dimethyl ether, and ethylene oxide
- general formula: R-O-R’
- R’ is an alkyl or a phenyl group different or same as R
- Ethers can be thought of derivatives of water (where 2 hydrogen atoms are replaced by alkyl groups)
- dimethyl ether= HC3-O-CH3
- Ethylene oxide= H2C-O-CH2 (da is auch eine Verbindung zwischen den beiden C’s)
