Metamerism Definition and Identification
Metamers are a specific type of structural isomerism. Molecules are classified as metamers if they possess the same molecular formula and the same functional group, but differ in the structure of the alkyl or aryl groups attached to the functional group. This typically occurs with functional groups like ethers (-O-), thioethers (-S-), secondary amines (-NH-), ketones (-CO-), and esters (-COO-).
Analyzing Molecular Pairs for Metamerism
Let's examine the given pairs to identify the metamers:
Option 1 Analysis: $CH_3OCH_2CH_2CH_3 \text{ and } CH_3CH_2OCH_2CH_3$
- Molecule A: $CH_3OCH_2CH_2CH_3$
- Molecular Formula: $C_4H_{10}O$
- Functional Group: Ether (-O-)
- Alkyl Groups: Methyl ($CH_3-$) and Propyl ($CH_2CH_2CH_3$)
- Molecule B: $CH_3CH_2OCH_2CH_3$
- Molecular Formula: $C_4H_{10}O$
- Functional Group: Ether (-O-)
- Alkyl Groups: Ethyl ($CH_3CH_2-$) and Ethyl ($CH_3CH_2-$)
Both molecules share the same molecular formula ($C_4H_{10}O$) and the same functional group (ether). They differ solely in the arrangement of alkyl groups around the oxygen atom. Therefore, $CH_3OCH_2CH_2CH_3$ and $CH_3CH_2OCH_2CH_3$ are metamers.
Analysis of Other Options (Briefly)
- Option 2 ($CH_3CH_2CH_2CH_3$ and $CH_3CH(CH_3)CH_3$) are alkanes; they are chain isomers (both $C_4H_{10}$) but not metamers as they lack a suitable divalent functional group.
- Option 4 ($CH_3CH_2CH_2OH$ and $CH_3CH(OH)CH_3$) are alcohols; they are positional isomers (both $C_3H_8O$) differing in the position of the -OH group, not metamers.
- Option 3 involves an image which is not required for identifying metamerism based on the provided correct answer.
Conclusion
The pair of molecules that exhibits metamerism among the choices is $CH_3OCH_2CH_2CH_3$ and $CH_3CH_2OCH_2CH_3$, as they are both ethers ($C_4H_{10}O$) with different alkyl group combinations around the oxygen atom.
Similar Questions
Select the reagents that reduce nitriles to primary amines :
A. (i) $LiAlH_4$ ; (ii) $H_2O$
B. $Sn + HCl$
C. $H_2 / Ni$
D. $Na(Hg) / C_2H_5OH$
E. $Br_2 / \text{aq. } NaOH$
Choose the correct answer from the options given below :The major product Z formed in the following sequence of reactions is :
$$C_2H_6 \xrightarrow{Cl_2, \text{UV light}} X \text{ (monochlorinated product)} \xrightarrow{NH_3} Y \xrightarrow{(i) NaNO_2, HCl, (ii) H_2O} Z$$- Compound P ($C_8H_8O$) gives a red orange precipitate with 2,4-DNP reagent and it does not reduce Fehling's reagent. On drastic oxidation with chromic acid, P gives an aromatic product Q that produces effervescence on treating with aq. $NaHCO_3$. Compounds P and Q, respectively, are :
The correct IUPAC name of the following compound is :
In the following reaction sequence, X and Z respectively are :
The number of chlorine atoms present in the organic products X and Y of the following reactions, respectively, are :
Two products X and Y are formed in the following reaction sequence.
The suitable method that can be used for the separation of products X and Y is :List I (Reactions) List II (Reagents) A. 
I. (i) oleum, (ii) $NaOH, \Delta$, (iii) $H^+$ B. $CH_3COOH \rightarrow CH_3CH_2OH$ II. (i) $O_3$, (ii) $H_2O/H^+$ C. $CH_3CH_2CH_2OH \rightarrow $ 
III. (i) $CH_3OH, H^+$, (ii) $H_2$, catalyst D. 
IV. (i) conc. $H_2SO_4, \Delta$, (ii) $H_2O$ Match List I with List II.
The following two reactions give the same foul smelling product Z.
$$C_2H_5Cl \xrightarrow{X} Z$$
X and Z, respectively, are :- Given below are two statements:
Statement-I : Oxidation of p-nitrotoluene with acidic $KMnO_4$ gives an acid that is stronger than benzoic acid.
Statement-II : Reduction of p-nitrotoluene with Sn/HCl followed by neutralization gives an amine that is more basic than aniline.
In light of the above statements, choose the most appropriate answer from the options given below.
Important Questions from Organic Chemistry
- In Dumas method for estimation of nitrogen, 0.50 g of an organic compound gave 70 mL of nitrogen collected at 300 K and 715 mm pressure. The percentage of nitrogen in the organic compound is ______ %.
(Aqueous tension at 300 K is 15 mm). Given below are two statements:
Statement I: The dipole moment of R-CN is greater than R-NC and R-NC can undergo hydrolysis under acidic medium to produce
Statement II: R-CN hydrolyses under acidic medium to produce a compound which on treatment with $\text{SOCl}_2$, followed by the addition of $\text{NH}_3$ gives another compound(x). This compound (x) on treatment with $\text{NaOCl/NaOH}$ gives a product, that on treatment with $\text{CHCl}_3\text{/KOH/}\Delta$ produces R-NC
In the light of the above statements, choose the correct answer from the options given below- Given below are two statements:
Statement I: Cross aldol condensation between two different aldehydes will always produce four different products.
Statement II: When semicarbazide reacts with a mixture of benzaldehyde and acetophenone under optimum pH, it forms a condensation product with acetophenone only.
In the light of the above statements, choose the correct answer from the options given below - $0.25 \text{ g}$ of an organic compound "A" containing carbon, hydrogen and oxygen was analysed using the combustion method. There was an increase in mass of $\text{CaCl}_2$ tube and potash tube at the end of the experiment. The amount was found to be $0.15 \text{ g}$ and $0.1837 \text{ g}$, respectively. The percentage of oxygen in compound A is ______ %. (Nearest integer)
(Given: molar mass in $\text{g mol}^{-1}$ $\text{H} : 1, \text{C} : 12, \text{O} : 16$) - Grignard reagent $\text{RMgBr (P)}$ reacts with water and forms a gas $\text{(Q)}$. One gram of Q occupies $1.4 \text{ dm}^3$ at STP. (P) on reaction with dry ice in dry ether followed by $\text{H}_3\text{O}^+$ forms a compound $\text{(Z)}$. 0.1 mole of $\text{(Z)}$ will weigh _________ g. (Nearest integer)
