Organic chemistry (lesson 1-2) Flashcards
What are the inorganic exceptions?
- oxides of carbon(CO, CO₂), carbonates (CO₃), cyanides (CN) and carbides(C₂)
- those which don’t include C-C or C-H bonds
Why might a compound be inorganic?
It is lacking both carbon-carbon (C-C) and carbon-hydrogen (C-H) covalent bonds.
What are organic compounds?
organic compounds are those in which carbon atoms are almost always bonded to each other, to hydrogen atoms and to a few other atoms (O, N, S, P).
What is the formula for Alkanes?
CₙH₂ₙ₊₂
eg) C₅H₁₂, C₂₀H₄₂, etc.
What are the characteristics of Alkanes?
- They are hydrocarbons containing only single bonds
- They are saturated
*can be long continuous chains, branched chains or ring structures (cycloalkanes)
- They are nonpolar and therefore not soluble in water.
- relatively unreactive because the single bonds are very stable
- LDF increases when there are more e⁻
*As you move down the homologous series, boiling and melting points increase, and it goes from gas -> liquid -> solid
- Liquid alkanes are very good solvents for other hydrocarbons
How do different structures influence boiling point?
Higher Boiling point factors:
- Symmetry of structure; symmetrical branched alkanes will typically have BP’s higher than unsymmetrical branched alkanes
- straight-chain alkane, as opposed to branched-chain alkane will have a higher BP due to greater surface area in contact between adjacent molecules.
- “stronger” bonds (double bond, triple bond etc.)
- Dipole-Dipole interactions contribute to higher boiling points of polar substances
- Hydrogen bonding significantly influences boiling points and solubilities
What are the characteristics of Alkenes?
- Hydrocarbons containing one or more double bond
- They are unsaturated
- Can be long continuous chains, branched chains or ring structures (cycloalkenes),
*They are nonpolar therefore not soluble in water.
- lower boiling point than alkanes because they have fewer e- which makes the LD forces of attraction weaker.
- more reactive and less stable than alkanes due to greater repulsion between electrons and lengthening (they want to repel)
What is the formula for alkenes?
CₙH₂ₙ
What is the formula for Alkynes?
CₙH₂ₙ₋₂
What are the characteristics of Alkynes?
- They are hydrocarbons containing one or more triple bonds
- they are unsaturated
- can be long continuous chains, branched chains
- nonpolar
- very reactive (more reactive than alkanes and alkenes) due to very high repulsion due to 6 electrons in the same area.
- boiling points are higher because of the linear structure and nature of triple bonds
What are the characteristics of Aromatics
- They are hydrocarbons containing one or more
benzene rings, C₆H₆. - They are nonpolar
- characterized by strong aromas
- all bonds are the same length and strength
- unknown reactivity
when does LDF increase?
when there are more e-
What is the diagnostic test to determine if a substance is an alkane vs alkene?
use KMnO₄ (aq) or Br₂
- alkenes (double bond) will react with these substances causing a noticeable colour change, alkanes will not.
For geometric isomers in alkenes, what is the prefix for the two different types of geometric isomers?
trans –> different sides
cis –> same side
uses for alkanes
natural gas (primarly methane), BBQ’s (propane), lighter fluid (butane), gasoline, etc.
good for making plastics, lubricants
uses for alkenes
- plastics (PVC), steroids, welding torches
- ethylene made from ethane cracking
uses for alkynes
- welding torches
uses for aromatics
ASA, amphetamines, adrenaline, anesthetics
moth balls, TNT
Wintergreen, menthol, vanilla, cinnamon
SPF in sunscreen
What are some characteristics of determining organic compounds?
- Organic compounds are those in which carbon atoms are almost always bonded to each other, to hydrogen and a few other atoms (Oxygen, Nitrogen, Sulfur, Phosphorous)
- All contain covalent bonds
why is carbon unique?
It can bond with other carbon atoms to form long chains, rings, spheres, tubes, sheets etc
It can form combinations of single, double and triple bonds (no other element does this!!)
Polar bonds are formed when…
there is an uneven pull on e⁻ within a molecule
Polar compounds are formed when the polar bonds within a molecule…
do not cancel each other out
can polar compounds dissolve in water?
Yes, The presence of dipole-dipole forces and hydrogen bonding will allow polar compounds to dissolve in water, since water is also polar
can non-polar compounds dissolve in water?
no, non-polar compounds only have LD forces between molecules and will not dissolve in water
