Rings of carbon are formed when a group of hydrocarbon come together to form a enclosed shape for example a hexagon. Their general formulais CnH2n, and when naming them, just add the prefix "CYCLO" infront of the main branch's name. for example, if a propane carbon chain has formed a triangle, it would be named as cyclopropane.
Cyclopropane
The cyclic hydrocarbons are more reactive, less stable and can also be branched. Cyclic hydrocarbons need at least three carbon atoms for it to form a ring.
When naming the compound, you can start from carbon atom and go clockwise or counter-clockwise. If there is only one side group, you do not need to put a number because we assume it starts at the very first carbon. When there is more than one side group, count clockwise or counter-clockwise from the first side group so that the lowest numbers are used.
cyclohexanone
Cyclic substituents are named the same way as they are in simple chains.
If there is a tie, we always sort them by alphabetical order.
Alkenes and Alkynes do not need numbers unless there is more than one double/triple bond because we always assume the bond starts from the first carbon.
Aromatics:
They usually have pleasant odours and contains at least one benzene ring (C6H6) which is a cyclohydrocarbon with 3 double bonds between carbon atoms.
The double bonds are delocalized so they can go anywhere and they are less reactive than cycloalkenes and cycloalpynes because of this.
Benzene
When naming aromatics, we name all the side groups first and then end with benzene.
If the benzene is a side group, we call it phenyl.
This video will sum up what we learned and is a great study guide for the test~! Enjoy
Carboxylic Acids
contain a double bonded oxygen with a carbon, and a single bonded base
To name this molecule, you drop the -e of a prefix and add -oic acid
eg ) ethanoic acid
Esters
Similar to carboxylic acids, but in stead you replace the base with an oxygen
Name from where this molecule is closer to the end of a chain. Then add -thyl and ends with -oate.
eg) methyl pentanoate
Ethers
contain an oxygen joining two hydrocarbon groups. Same as naming standard naming rules, change the ending to -oxy.
eg) 1-methoxyethane
CH3-CH2-O-CH3
Look at how the oxygen is attached to the CH3 closer to the right. So it is methoxy. The left over side group is ethane. The name of the whole chain is called 1-ethoxyethane.
Lastly, we covered amines in class. Here's a brief introduction of how to name amines.
Functional Groups- organic compounds that contain elemtns other than C and H
most reactive part of the molecule
may be single atom (F, Cl, Br) or groups of atoms (NO2, NH2)
Halide and Nitro Compounds
*use di-, tri-, tetra- in front for multiple groups
Halogens
F = fluoro
Cl = chloro
Br = bromo
I = iodo
Nitro
NO2 = nitro
Ex/ 1, 1, 2, 2-tetrabromo ethane
Properties of Halogenated Compound
1. Insoluble in water
2. Unreactive
3. Compounds containing Cl or Br are more reative
4. Compounds containing I are very reactive
Properties of Nitro Compounds
1. Normally insoluble in water
2. Unreactive
3. Explosive
4. Have a pleasant odour
Alcohols
- an organic compound that contains OH functional group
- named by
using the longest carbon chain containing the OH group
replacing "e" ending with "ol"
multiple OH: diol, triol
*alcohol chains has to have the lowest number possible
Ex/ 1, 2, 3-butanetriol
Properties of Alcohols
1. Soluble. As you get longer chains, it becomes more insoluble.
2. Poisonous
Aldehydes and Ketones
- organic compounds containing carbonyl funtional group (double bonded oxygen)
Aldehydes
- has a double bonded oxygen at the end
- -al ending
Ex/ hexanal
Ketones
- double bonded oxygen not on either end
- -one ending
Ex/ 3-pentanone
Properties of Aldehydes and Ketones
1. Both partially soluble
2. Aldehydes are very active, and are easily converted or "oxidized" to Carboxylic Acids
3. Ketones are relatively unreactive
Organic compounds are the compounds containing carbon in it.When the organic compound is burned, it produces carbon dioxide. It has low melting points, and it is weak or non- electrolytes.
Organic compound forms chains of carbon atoms in three different patterns:
Alkanes is the hydrocarbon ( containing H & C). Alkanes are satuated, meaning that all carbon atoms are bonded by single bonds so no other atoms can bond to it. There are variety of types and different ways to represent them.
Their name end in '-ane' (ex, methane, octane)
To name Alkanes, put prefixes infront of '-ane' according to the number of carbons.
Series of organic compounds with a similar general formula and properties ( just like the one above) are called the homologous series.
☆Alkyl Group
Alkyl group is the alkane that has lost one hydrogen. This group occurs in the branched hydrocarbons.
Naming Hydrocarbons
Here is the steps you should take when naming the hydro carbons with only one bond.
1. Find and name the longest continuous carbon chain and place at the end of the name. (ex. diagram below; carbons in the blue rectangle → butane)
2. Identify and name groups (ex. diagram below; red circle → methyl) attached to the chain.
3. Number the chain from nearest side (from the group) to the other.
4. Represent the location of each side group by an approperiate numbers and names.
5. Assemble the name, listing groups in alpha betical order.
Ex. 2,3-dimethylbutane
*more than one of the same kind of alkyl grops are represented using prefixes (ex. di, tri,)
☆Alkenes
Alkenes are just like the Alkanes, but with one or more double bonds.
Alkenes are unsaturated hydrocarbons and are generally very reactive.
Alkenes end with "-ene"
Example: These are all homologous alkenes. As you can see, they all have double bonds.
☆Alkynes
Similarly, Alkynes are the hydrocarbon with one or more triple bonds.
Alkynes are unsatuated and they end with "-yne"
Example:
You would take same steps to name Alkenes and Alkynes as Alkanes EXCEPT that you are numbering the chain from the side closer to the double or triple bond. For example, on the example above, there is a triple bond located closer to the left end of the chain. So, you would have to number chain from left to right.... the name would be5-methal-2-pentyne
If the geometry happen to have more than one bond, state the position of the bonds and add prefixes in front of "-ene" or "-yne" (ex. 3,7-decadiene)
Since same formula can have different geometry, (= Gemetric isomers) "Cis" and "Trans" are put in front of the name of hydrocarbons to identify the geometry.
This kind of geometry, with larger group (☆) above is named with "Cis"
This kind of geometry, with larger group (☆) located vertically is named with "Trans"
No need to write "Cis" nor "Trans" for this kind :)
This video will help you understand more about hydrocarbons.
Electronegativityrefers to the attraction an atom has for the shared ppair of electrons in a chemical bond.
As you can see, electronegativity increases as you move diagonally from the bottom left (Francium) to the top right (Fluorine) of the periodic table.
Pauling scale is the most common scale used to measure the atom's electronegativity. It ranges from 0.7 to 4.0, meaning that the electronegativity of Francium is 0.7, whereas the electronegativity of Fluorine is 4.0.
Atoms with higher electronegativity attract its electrons and neighbouring electrons more than those with lower electronegativity. ALSO, stronger attraction means that the electrons in the atoms with higher electronegativity are more difficult to remove. More energy is needed to remove the electrons, so the atoms with higher electronegativity would have higher ionization energy as well.
From calculating the electronegativity difference between two or more elements involved in the chemical bond, you can find out what type of chemical bond the atoms are most likely to have.
If electronegativity difference < 0.5, it is a COVALENT BOND
If electronegativity difference > 1.8, it is an IONIC BOND
But what if 0.5 < electronegativity difference < 1.8 ?
It is called aPolar Covalent Bond and it is the another type of covalent bonding that involves unequal sharing. In this type of chemical bonding, the atom with higher electronegativity pulls the electrons in the bond and electron that are shared towards itself. Polarityis used to describe a molecule's balance, just like density. ( Which atom has more electronegativity and which has less )
Electronegativity difference between Se and F = | 2.55 - 3.98 |
= 1.43 ⇒ this is a polar covalent bond
Draw a Lewis Diagram to figure out how many electrons do they share.
In Selenium difluoride, these electrons are shared.
Draw a line to represent a single bond.
In Polar Covalent Bond, atom with higher electronegativity forms a partly negative charge, and atom with lower electonegativity forms a partly negative charge. To show which one has the partly positive and negative charge, δ+ or δ- is marked above each atom.
Also, an arrow is drawn from atom that is δ+ to the atom that is δ- to show that the atom that is δ- is pulling the electrons.
1) Positively charges and negatively charges create repulsion. 2) Different charges affect each other. 3) Two opposite charges do not easily attract when they have a great distance. 4) When the particles contain greater charges, more force attract them together.
Ionic bonds
- An electron is transferred into another element when opposite charges of elements join together. - They either gain or lose electrons to form a closed shell. - Very strong, not easy to break
Covalent bonds
- also called non polar bonding
- share equal amount of electrons - sharing with each other to form full electron shell - due to very large electronegativities, they do not lose or gain electrons easily.
- have lower melting points
- Intermolecular forces hold intramolecular covalent bonds together
