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