Question:
Highest boiling point among these isomers (C$_{5}$H$_{12}$):
Highest boiling point among these isomers (C$_{5}$H$_{12}$):
Show Hint
Straight chain = High Surface Area = High Boiling Point. Branching always lowers the boiling point in isomers.
Updated On: May 5, 2026
- n-pentane
- neopentane
- isopentane
- 2-methylbutane
Show Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
Step 1: Concept
Boiling points in alkanes are primarily determined by the strength of London dispersion forces (intermolecular forces).
Step 2: Meaning
These forces are proportional to the molecular surface area; a larger surface area allows for more points of contact between molecules.
Step 3: Analysis
n-pentane is a straight-chain molecule with the maximum surface area. Branching (as seen in isopentane and neopentane) makes the molecule more spherical/compact, significantly reducing the surface area and weakening the intermolecular attractions.
Step 4: Conclusion
Because n-pentane has the most extensive surface contact among its isomers, it requires the most energy (highest temperature) to overcome these forces and boil. Final Answer: (A)
Boiling points in alkanes are primarily determined by the strength of London dispersion forces (intermolecular forces).
Step 2: Meaning
These forces are proportional to the molecular surface area; a larger surface area allows for more points of contact between molecules.
Step 3: Analysis
n-pentane is a straight-chain molecule with the maximum surface area. Branching (as seen in isopentane and neopentane) makes the molecule more spherical/compact, significantly reducing the surface area and weakening the intermolecular attractions.
Step 4: Conclusion
Because n-pentane has the most extensive surface contact among its isomers, it requires the most energy (highest temperature) to overcome these forces and boil. Final Answer: (A)
Was this answer helpful?
0
0
Top TS EAMCET Chemistry Questions
- A, B and C are three biomolecules. The results of the tests performed on them are given below :A, B and C are respectively :
Molisch's lest Barfoed Test Biuret Test A Positive Negative Negativde B Positive Positive Negative C Negative Negative Positive - 1 mole of $H_2$ and 2 moles of $I_2$ are taken initially in a 2 litre vessel. The number of moles of $H_2$ at equilibrium is 0.2. Then the number of moles of $I_2$ and HI at equilibrium is
- The pH of a buffer containing equal molarconcentration of a weak base and its chloride ( $K_b$ for weak base = $2 \times 10^{-5}$, log 2 = 0.3) is
- Atomic radius (pm) of Al, Si, N and F respectively is
- Consider the following electrode process of a cell, $ {Cl^{-1} -> \frac{1}{2} Cl_2 + e^{-}}$ $ {[MCl + e^{-} -> M + Cl^{-} ] }$ If EMF of this cell is $-1.140\, V$ and $E^0$ value of the cell is $-0.55\,V$ at $298\,K$, the value of the equilibrium constant of the sparingly soluble salt MCl is in the order of
View More Questions
Top TS EAMCET Hydrocarbons Questions
- An alkene ‘X’ (C\(_4\)H\(_8\)) does not exhibit cis/trans isomerism. Reaction of ‘X’ with Br\(_2\)/CCL\(_4\), followed by reaction with reagent ‘Y’ gave ‘Z’ (C\(_6\)H\(_6\)). What are ‘Y’ and ‘Z’ respectively?
- An alcohol 'X' (C$_4$H$_{10}$O) reacts with conc. HCl at room temperature and gives chloride. 'X' on dehydration followed by ozonolysis gives 'Y' and 'Z'. Find 'Y' and 'Z'.
- Consider the following statements
Statement I: Benzene undergoes electrophilic substitution with excess chlorine in the presence of anhydrous AlCl$_3$
Statement - II: Benzene also undergoes electrophilic substitution with chlorine in the presence of UV light.
The correct answer is - The empirical formula of the compound 'D' formed in the given reaction sequence is
C₂H₄ \(\xrightarrow{Br_2|CCl_4}\) A \(\xrightarrow{(i) alc. KOH (ii) NaNH_2}\) B \(\xrightarrow{cyclic\;polymerization}\) C \(\xrightarrow{Cl_2(excess), dry\;AlCl_3, dark, cold}\) D - An alkyne has the molecular formula C₆H₁₀. The number of 1-alkyne isomers (excluding stereoisomers) possible for it is
View More Questions
Top TS EAMCET Questions
- A bag contains $5$ red balls, $3$ black balls and $4$ white balls are drawn at random. The probability that they are not of same colour is
- If $cosec\, \theta - \cot \theta = 2017$, then quadrant in which $\theta $ lies is
- If $a$ is a unit vector, then $| a \times \hat{ i }|^{2}+| a \times \hat{ j }|^{2}+| a \times \hat{ k }|^{2}=$
- $A$ straight line makes an intercept on the $Y$-axis twice as long as that on $X$-axis and is at a unit distance from the origin. Then the line is represented by the equations
- Let $S$ and $S'$ be the foci of an ellipse and B be one end of its minor axis. If $SBS'$ is an isosceles right angled triangle then the eccentricity of the ellipse is
View More Questions