what reagent and the reaction condition that would distinguish between these compounds...?

Question

1)Benzene and ethylbenzene
2) 1-butyne and 2-butyne
3) 2-methylpentane and 2-methyl-2-pentane
4)toluene and 1-methylcyclohexane

Also, can you show me the equations?

in no. 3, the second compound is 2--methyl-2-pentene... typo error...sorry..

Answer 1

Lancenigo di Villorba (TV), Italy

QUESTION 1)
Benzene and ethylbenzene belong to arenes the term defining aromatic hydrocarbons.
A simple lab's way to distinguish them it interests the "lateral chain" of ethylbenzene. As you know, the latter can undergo "radicalic substitution".
In your case, benzene shows not "lateral chain" so ethylbenzene only can react with chlorine gas in gas phase (U.V. lamp catalyzes the process), as follows :
C6H5CH2CH3(g) + Cl2(g) ---> C6H5CH(Cl)CH3(g) + HCl(g)
where C6H5 means "aromatic phenyl group".
You obtain a heavier vapour (e.g. C6H5CH(Cl)CH3, alpha-phenyl-ethyl chloride) than the reactants ; benzene reacts not.

QUESTION 2)
The test interests a Drexel's apparatus. In this particular vessel you put an hydro-alcoholic solution of silver nitrate. Now, you bring one among the two hydrocarbons in a manner that it flows up in the solution. One and only one among the two unsaturated gas can react with the solution as showedby a pale precipitated body (e.g. silver compound of reacted gas).
CH#CHCH2CH3(g) + AgNO3(l) --->
---> AgC#CHCH2CH3(s) +HNO3(l)
where # symbol means "C-C triple bond", so I shown 1-butyne's reaction. This type of unsaturated hydrocarbons is "terminal alkynes"...1-butyne belongs to "terminal alkynes", 2-butyne does not.

QUESTION 3)
I THINK YOU MEANT :
2-methylpentane and 2-methyl-2-pentene.
If I understood right, you want distinguish among one alkane and one alkene. In "Electrophilic Addiction" 's reactions you understood that alkenes undergo when mixed with several reactants : among these there is bromine's solutions. A bromine's solution in carbon tetrachloride it will be your reactant : one and only one among hydrocarbons will show decoloration behaviour. The reaction involved is the following :
CH3C(CH3)=CHCH2CH3(g) + Br2(l) --->
---> CH3C(CH3)CHCH2CH3(l)
...............|............|
..............Br.........Br
2-methyl-2-pentene react decolorating (e.g. it forms 2-methyl-2,3-dibromo-pentane) the reddish bromine's drops added while 2-methylpentane does not.

QUESTION 4)
Now, you compare one arene (e.g. toluene) with one "alicyclic" hydrocarbon (e.g. methylcyclohexane).
The simplest lab's test which I thought is a particular feature of "Friedel-Craft's mechanism", I think to "Gomberg's reaction".
In a glass-balloon you mix one or the other hydrocarbon with "chlorinated mixture". For obtaining the latter you must put several spoons of aluminium chloride in an satisfactory liquid amount of carbon tetrachloride.
By means of warm-bath operations, you may obtain a change of colouration. In effect, arenes are hydrocarbons containing aromatic rings which permitting formation of particular carbocations.
The latter are responsible for the final colorations : this is the case of toluene, by means of the following reaction :
3 C6H5CH3(l) + CCl4(l) ---> (CH3C6H4)3C+Cl-(l) + 3 HCl(g)
where the carbocation may be (CH3C6H4)3C+Cl-
(e.g. chloro-tri-tolyl-methane).
Methylcyclohexane react not (e.g. it is not an arene).

I hope this helps you.

Answer 2

1) Ethyl benzene will react speedily with NBS.

2) 1-butyne will give a precipitate with Tollens reagent

3) I think the 2nd compound is a pentene isomer.

It will react with Br2.

4) Toluene will react with NBS.

Answer 3

hi folowing are the respond [a] benzene does no longer get oxidation with baeyer reagent .yet while ethyl benzene is oxidised with baeyer reagent [alkaline kMnO4} it provides Benzoic acid which grant effervescence of CO2 with bicarbonate [b] one butyne has one acidic hydrogen so it react with ammonical silver nitrate and varieties white ppt .yet 2 -butyne does no longer react [c] 2-methyl a million-pentene if oxodised with warm KMnO4 answer it varieties HCOOH and a pair of -butaneone ,being a terminal alkene yet in comparable circumstances 2-methyl 2-pentene provides Propanal and a pair of-propanone [d] toluene deos no longer get oxidation by way of bayer reagent yet cyclo hexene does

Answer 4

try Von baeyer's reagent...

Answer 5

go to:
http://www.chem.umn.edu/class/2301/barany01/lecture29.pdf

I hope this will help you!!