Which among the following has highest boiling point?
- \( \text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_3 \)
- \( \text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{–OH} \)
- \( \text{CH}_3\text{CH}_2\text{CH}_2\text{CHO} \)
- \( \text{H}_5\text{C}_2 - \text{O} - \text{C}_2\text{H}_5 \)
The Correct Option is B
Approach Solution - 1
To determine which compound has the highest boiling point among the given options, we need to consider the types of intermolecular forces present in each compound. Generally, stronger intermolecular forces result in higher boiling points.
- \(\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_3\): This is butane, an alkane. Alkanes have weak van der Waals (dispersion) forces due to their non-polar nature. Thus, it has a relatively low boiling point.
- \(\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{–OH}\): This is butanol, an alcohol. Alcohols can form hydrogen bonds due to the presence of the hydroxyl group (-OH). Hydrogen bonds are stronger than van der Waals forces, leading to a higher boiling point.
- \(\text{CH}_3\text{CH}_2\text{CH}_2\text{CHO}\): This is butanal, an aldehyde. Aldehydes have dipole-dipole interactions due to the carbonyl group, which are stronger than van der Waals forces but weaker than hydrogen bonds.
- \(\text{H}_5\text{C}_2 - \text{O} - \text{C}_2\text{H}_5\): This is diethyl ether, an ether. Ethers have dipole-dipole interactions, similar to aldehydes, but no hydrogen bonding.
Among these, butanol will have the highest boiling point due to the presence of hydrogen bonding, which is a strong intermolecular force.
Therefore, the correct answer is \(\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{–OH}\).
Approach Solution -2
The boiling point of a compound depends on various factors such as molecular weight, type of bonding, and intermolecular forces. In this case, let’s analyze the given options:
Option (1) CH$_3$CH$_2$CH$_2$CH$_3$ (Butane): This is a hydrocarbon with weak Van der Waals forces. It has a relatively low boiling point due to the absence of hydrogen bonding.
Option (2) CH$_3$CH$_2$CH$_2$CH$_2$OH (Butanol): This compound contains an --OH (hydroxyl) group, which allows for hydrogen bonding between molecules. Hydrogen bonding significantly increases the boiling point compared to compounds with only Van der Waals interactions.
Option (3) CH$_3$CH$_2$CH$_2$CHO (Butanal): This compound has a carbonyl group (C=O), leading to dipole-dipole interactions. However, these interactions are weaker than the hydrogen bonding present in alcohols.
Option (4) C$_2$H$_5$OC$_2$H$_5$ (Diethyl ether): This compound contains an ether linkage, resulting in weak dipole-dipole interactions, but it lacks hydrogen bonding.
Conclusion: Among the given compounds, CH$_3$CH$_2$CH$_2$CH$_2$OH (butanol) has the highest boiling point due to the presence of strong intermolecular hydrogen bonding.
Top Questions on Alcohols, Phenols and Ethers
- An alcohol X (C$_4$H$_{10}$O) reacts with Conc.HCl/ZnCl$_2$ to give corresponding chloride. X on dehydration forms Y, which reacts with Baeyer's reagent to give Z. What is Z?
- TS EAMCET - 2025
- Chemistry
- Alcohols, Phenols and Ethers
Given below are two statements:
Statement I: Dimethyl ether is completely soluble in water. However, diethyl ether is soluble in water to a very small extent.
Statement II: Sodium metal can be used to dry diethyl ether and not ethyl alcohol.
In the light of the given statements, choose the correct answer from the options given below:- JEE Main - 2025
- Chemistry
- Alcohols, Phenols and Ethers
- Isopentyl alcohol reacts with reagent X → carboxylic acid → decarboxylation → Y. Reaction of Y with Z → t-butyl alcohol. Identify X and Z.
- TS EAMCET - 2025
- Chemistry
- Alcohols, Phenols and Ethers
- In which of the following, intramolecular hydrogen bonding is present?
- TS EAMCET - 2025
- Chemistry
- Alcohols, Phenols and Ethers
- Distinguish between Alcohol and Phenol.
- Bihar Board XII - 2025
- Chemistry
- Alcohols, Phenols and Ethers
Questions Asked in JEE Main exam
Consider the following sequence of reactions :
Molar mass of the product formed (A) is ______ g mol\(^{-1}\).- JEE Main - 2025
- Organic Chemistry
- A group 15 element forms \( d\pi - d\pi \) bond with transition metals. It also forms a hydride, which is the strongest base among the hydrides of other group members that form \( d\pi - d\pi \) bonds. The atomic number of the element is ________________________.
- JEE Main - 2025
- Chemical bonding and molecular structure
- Let \( M \) denote the set of all real matrices of order 3 x 3 and let \( S = \{-3, -2, -1, 1, 2\} \). Let
\( S_1 = \{A = [a_{ij}] \in M : A = A^T \text{ and } a_{ij} \in S, \forall i, j\} \),
\( S_2 = \{A = [a_{ij}] \in M : A = -A^T \text{ and } a_{ij} \in S, \forall i, j\} \),
\( S_3 = \{A = [a_{ij}] \in M : a_{11} + a_{22} + a_{33} = 0 \text{ and } a_{ij} \in S, \forall i, j\} \).
If \(n(S_1 \cup S_2 \cup S_3) = 125\), then \( \alpha \) equals:- JEE Main - 2025
- Linear Algebra
- Let the lines \[ 3x - 4y - \alpha = 0, \quad 8x - 11y - 33 = 0, \quad 2x - 3y + \lambda = 0 \] be concurrent. If the image of the point \( (1, 2) \) in the line \[ 2x - 3y + \lambda = 0 \text{ is } \left( \frac{57}{13}, \frac{-40}{13} \right), \text{ then } |\alpha \lambda| \text{ is equal to:} \]
- JEE Main - 2025
- Matrices and Determinants
In the first configuration (1) as shown in the figure, four identical charges \( q_0 \) are kept at the corners A, B, C and D of square of side length \( a \). In the second configuration (2), the same charges are shifted to mid points C, E, H, and F of the square. If \( K = \frac{1}{4\pi \epsilon_0} \), the difference between the potential energies of configuration (2) and (1) is given by:
- JEE Main - 2025
- Electromagnetic Field (EMF)