Naming compounds using IUPAC system

Answer 1

To name any alkane, simply follow these 10 rules (go through them in order):

1) The following names are the basis of the system. The name depends on the number of carbon atoms:

1 carbon CH4: methane

2 carbons C2H6: ethane

3 carbons C3H8: propane

4 carbons C4H10: butane

5 carbons C5H12: pentane

6 carbons C6H14: hexane

7 carbons C7H16: heptane

8 carbons C8H18: octane

9 carbons C9H20: nonane

10 carbons C10H22: decane

2) For alkanes with branched carbon chains, determine which chain is the principal chain. The principal chain is the longest contiguous carbon chain.

3) If two or more chains in the structure have the same length, the principal chain is the one with the most branches.

4) Number the carbon atoms of the principal chain from one end to the other in the direction that gives the lowest number to the first branching point.

5) Name each branch and identify the carbon number on the principal where it is attached. For branch names, use the names from Part 1, but remove "ane" and add "yl" (e.g. methyl, ethyl, propyl, etc.) There are certain special groups with their own names, such as isopropyl, tert-butyl, and isobutyl (look these up for more information).

6) Construct the molecule name by adding the carbon number of the principal chain where it attached, then a hyphen, the name of the branch, and finally the name of the principal chain. That is:

branching #

hyphen

branch name

principal chain name

Note that there are NO SPACES, such that the branch name and principal chain name form one word.

7) If the principal chain contains more than one branch, each branch receives its own number. Use the prefixes di, tri, tetra for 2,3, or 4 identical branches (respectively)

8) If substituent groups at more than one carbon of the principal chain, alternative number schemes are compared. The one that gives the lowest value is used.

9) Substituent groups are cited in the name in alphabetical order, regardless of their order of occurrence in the molecule. Prefixes di, tri, tetra, and tert are ignored, but prefixes iso, neo, and cyclo are not!

10) If number of different groups is not resolved by other rules, first cited group gets the lowest number.

11) if more than one same branches gets same no. from either side then number the chain such that the sum of the number of the branched carbon must be lower.

Answer 2

# find the root word (ending in-ane) in the hydrocarbon name. then write the longest carbon chain to create parent structure. # Number the carbons on the parent chain. (you want the branches on the lower numbers, can be either left to right, or right to left)

# Identify the substituent groups. Attach the substituents to the numbered parent chain at proper positions.

# Add hydrogens as needed

Answer 3

IUPAC ( international union of pure and applied chemistry) has published recommendation for the namig of both organic and inorganic chemical compounds. Some of the naming conventions have gained wide acceptance others have not. There are various summaries of theh recommendations on wikipedia but these are generally incomplete. IUPAC publish these "red bookss" as they are called and these are available as down loads.

Answer 4

IUPAC nomenclature depends on a carbon numbering system:

1 - meth

2 - eth

3 - prop

4 - but

5 - pent

6 - hex

and so on. Alkanes use the ending -ane. So CH4 becomes Methane, C2H8 Ethane, etc.

Answer 5

Prefixes (based on number of Carbons):

1. Meth
2. Eth
3. Prop
4. But
5. Pent
6. Hex
7. Hept
8. Oct
9. Non
10. Dec
11. Undecane
12. Dodecane
13. Triacontane

To name when only given an illustration:

Count the number of Carbon atoms, then apply the prefix that correspons to that number.

Example:

(dashes between Carbon atoms represent bonds. H's represent Hydrogen atoms.)

CH3-CH2-CH2-CH2-CH2-CH3

Count Carbon (C) atoms: 6

Identify corresponding prefix: 6 --> Hex

Apply prefix and suffix: (6-->Hex) + (Alkane--> ane) = Hexane

To name when given only the formula:

Identify the number of Carbon (C) atoms and apply the corresponding prefix.

Example:

C6H14

Identify the number of C's: 6

Apply prefix: 6--> Hex

Apply suffix: Alkane --> ane

Answer: Haxane

Naming Isomers

go through the same steps as when you are given the illustration, but instead of counting the entire number of C's, count only the longest chain. Then, identify the number of the Carbon atom off-which the branch projects.

Formula:(location of extention)(name of branch)(name of "backbone" chain)

Example:

(dashes between Carbon atoms represent bonds. Lines ejecting from Carbon atoms represent Hydrogen atoms.)

CH3

CH2

CH3-CH2-CH2-CH2-CH3

(the above illustration is an isomer of Heptane)

Count Carbon (C) atoms OF THE LONGEST CHAIN: 5

Identify corresponding prefix: 5 --> Pent

Apply prefix and suffix: (5--> Pent) + (Alkane--> ane) = Pentane

So far: (location of branch)(name of branch) Pentane

Count the number of Carbon (C) atoms in the branch (this does not include the already named chain): 2

Identify its corresponding Prefix: 2 --> Eth

Apply prefix and suffix: (2 --> Eth) + (branch --> yl) = Ethyl

So far: (location of branch) Ethyl-Pentane

Identify on which C atom the branch is connected (you can count from both ends, but always use the smaller number): the 1st

Apply to name--> 1-Ethyl-Pentane

To calculate the number of Hydrogen atoms when given only the name and no illustration:

Cx2 + 2

^# of Carbon atoms

Example: Butane

Identify the prefix: But --> 4

plug into equation: (4)2 + 2 = 10

Apply: Butane --> C4H10

Answer 6

Ch3ch2chch2ch3