Organic Nomenclature and Simple Reactions

  • Thread starter Shay10825
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  • #1
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Hello. Can someone please check my work and help me with these problems. I'm sorry it is so long.

Predict and balance the following organic equation.

--------------------------------------------------------

1. Ethanol (ethyl alcohol) is burned completely in air

C2H5OH + 3O2 > 2CO2 + 3H2O
--------------------------------------------------------

2. Propane gas is heated with chlorine gas

C3H8 + Cl2 > C3H7Cl + HCl

--------------------------------------------------------

3. Ethanol (ethyl alcohol) and methanoic acid (formic acid) are mixed and warmed

C2H5OH + CH3OH > CO2 + H2O
If this is correct then how do I balance it?
--------------------------------------------------------

4. Ethene gas is bubbled through a solution of bromine

C2H4 + Br2 > C2H4Br2
--------------------------------------------------------

5. Hydrogen gas is added to 2-pentene

H2 + C5H10 > C5H12
--------------------------------------------------------

6. Octane is burned in oxygen

2C8H18 + 25 O2 > 16CO2 + 18H2O
--------------------------------------------------------

7. 2-butene is combined with hydrogen gas in the presence of a nickel catalyst

C4H10 + H2 +Ni > ???

--------------------------------------------------------

8. Ethanoic acid is combined with propanol

C2H5OH + C3H7OH > CO2 + H2O
If this is correct then how do I balance it?
--------------------------------------------------------

9. An excess of chlorine gas is added to pure ethyne (acetylene) gas

Cl2 + C2H2 > C2H2Cl2
--------------------------------------------------------

10. A limited amount of liquid bromine is added to an excess of benzene (C6H6)

Br2 + C6H6 > C6H4Br2 + H2
--------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Name the following hydrocarbon compounds.

1. (CH3)2CHCl

dimethyl?? How do I name it with the Cl ??
--------------------------------------------------------

2. CH3C(CH3)2CH2C(CH3)2CH2CH2CH3

2,4 dimethylheptane
--------------------------------------------------------

3. CH3C(CH3)2CH - - C(CH3)CH2CH3

2,4 dimethylpentane
--------------------------------------------------------

4. CH3C --- CCH3

1,2 dimethylethane
--------------------------------------------------------

Thanks
 

Answers and Replies

  • #2
siddharth
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Shay10825 said:
Hello. Can someone please check my work and help me with these problems. I'm sorry it is so long.
Predict and balance the following organic equation.
--------------------------------------------------------
1. Ethanol (ethyl alcohol) is burned completely in air
C2H5OH + 3O2 > 2CO2 + 3H2O
That's right.
Shay10825 said:
--------------------------------------------------------
2. Propane gas is heated with chlorine gas
C3H8 + Cl2 > C3H7Cl + HCl
There can be more than 1 product here. This looks like the halogenation reaction. You will have to carry this out in the presence of sunlight
--------------------------------------------------------
Shay10825 said:
3. Ethanol (ethyl alcohol) and methanoic acid (formic acid) are mixed and warmed
C2H5OH + CH3OH > CO2 + H2O
If this is correct then how do I balance it?
No, this is not correct. Formic acid is HCOOH. CH3OH is methanol
--------------------------------------------------------
Shay10825 said:
4. Ethene gas is bubbled through a solution of bromine
C2H4 + Br2 > C2H4Br2
This is correct.

--------------------------------------------------------
Shay10825 said:
5. Hydrogen gas is added to 2-pentene
H2 + C5H10 > C5H12
Will there be a reaction? I think you would require a presence of a catalyst to notice any reaction.
--------------------------------------------------------
Shay10825 said:
6. Octane is burned in oxygen
2C8H18 + 25 O2 > 16CO2 + 18H2O
Products are right. I have not checked if it's balanced
--------------------------------------------------------
Shay10825 said:
7. 2-butene is combined with hydrogen gas in the presence of a nickel catalyst
C4H10 + H2 +Ni > ???
Refer question 5

--------------------------------------------------------
Shay10825 said:
8. Ethanoic acid is combined with propanol
C2H5OH + C3H7OH > CO2 + H2O
If this is correct then how do I balance it?
This is wrong. Ethanoic acid is CH3COOH. C2H5OH is Ethanol.
--------------------------------------------------------
Shay10825 said:
9. An excess of chlorine gas is added to pure ethyne (acetylene) gas
Cl2 + C2H2 > C2H2Cl2
Not completly correct.
You are adding an excess of Chlorine gas. Will the reaction stop here?

--------------------------------------------------------
Shay10825 said:
10. A limited amount of liquid bromine is added to an excess of benzene (C6H6)
Br2 + C6H6 > C6H4Br2 + H2
This is wrong. Benzene is aromatic. It will undergo substitution reactions rather than addition reactions.


Shay10825 said:
--------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Name the following hydrocarbon compounds.
1. (CH3)2CHCl
dimethyl?? How do I name it with the Cl ??
The longest Carbon chain is 3 carbons long. So it will be a substitited propane rather than dimethyl methane. I'll do this one and see if you can do the rest. The IUPAC name will be 2-Chloro Propane.
--------------------------------------------------------
Shay10825 said:
2. CH3C(CH3)2CH2C(CH3)2CH2CH2CH3
2,4 dimethylheptane
This is not correct. How many methyl groups are attached? 2 on the second carbon and 2 on the fourth carbon.
--------------------------------------------------------
Shay10825 said:
3. CH3C(CH3)2CH - - C(CH3)CH2CH3
2,4 dimethylpentane
This is wrong.
Look at the longest Carbon chain. Besides, there is a double bond. So it should be an alkene
--------------------------------------------------------
Shay10825 said:
4. CH3C --- CCH3
1,2 dimethylethane
There should be a triple bond right? So it's an alkyne not an alkane.
 
Last edited:
  • #5
GCT
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well I remembered that alkynes don't undergo electrophilic additions as well as the alkenes, the exact reason I do not recall at the moment. There are methods of addition (whether electrophilic or nucleophilic) but I remember that it involves some sort of metal catalyst. There are some important reactions with ethyne (such as the possibility of carbon carbon bond formation) but I wasn't familiar with it just reacting with a bromine molecule (I can't remember at the moment but a particular halogenated ethane or ethene isomer predominates between interconversions of isomers and is a byproduct of a laundry detergent or some other industrial chemical....that is before they stopped using it-that is tetra-chloroethane may be formed to a certain extent).
 
  • #6
siddharth
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GCT said:
well I remembered that alkynes don't undergo electrophilic additions as well as the alkenes, the exact reason I do not recall at the moment. There are methods of addition (whether electrophilic or nucleophilic) but I remember that it involves some sort of metal catalyst. There are some important reactions with ethyne (such as the possibility of carbon carbon bond formation) but I wasn't familiar with it just reacting with a bromine molecule (I can't remember at the moment but a particular halogenated ethane or ethene isomer predominates between interconversions of isomers and is a byproduct of a laundry detergent or some other industrial chemical....that is before they stopped using it-that is tetra-chloroethane may be formed to a certain extent).
When I learnt this a couple of years ago in high school, I was taught that the addition of halogens to alkenes and alkynes is by the halonium ion intermediate (ie, the cyclic intermediate with the Br+ and the 2 carbons).

That is, in the first step the attacking species is Br+ which forms this cyclic halonium. Then, in the second step the Br- reacts with the halide ion to give the addition product.

So, I guess the reason why alkynes don't undergo electrophilic addition with halogens as well as alkenes is beacuse the intermediate formed with the alkynes is more strained and less stable than the intermediate formed from the alkenes.

In all my exams to date, I have been writing that the final product when excess halogens react with alkynes is the tetrahalo alkane. It was a suprise when you showed that it wasn't true for ethyne
 
Last edited:
  • #7
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Hey
i noticed you has the reaction for Propane + chloride = C3H7Cl + Hydrochloric acid

what is the name of C3H7Cl using the IUPAC system for naming
 
  • #8
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I belive you would refer to that one as either 1 or 2- chloro-propane depending upon the substitution location.
 
  • #9
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hey, thanks for the anwers

#3 should be C2H5OH plus CHOOH yield C2H5OOCH plus H2O, i think. Also, (CH3)2CHCl is 1-chloro-1-dimethylmethane. I'm not sure if you need the 1 though.
 
  • #10
chemisttree
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GCT, that's an excellent link.
I thought that tetrachloro ethane would be formed but your link disproves that.
How did you know that such a reaction occurs?
This is possible if acetylene is introduced into a chlorine atmosphere in an uncontrolled (thermally) manner. The reaction is exothermic enought to decompose the initially-formed dichloroethene to carbon black. Under controlled conditions, the dichloro or tetrachloro product can form. Addition of X2 across the triple and double bonds is achieved under lower temperature conditions by performing the reaction under dilution with cooling and with metal catalysts (copper, manganese, etc...).
 

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