Permanent hardness in water cannot be cured by :
- Boiling
- Ion exchange method
- Calgon's method
- Treatment with washing soda
The Correct Option is A
Solution and Explanation
Top Questions on Hydrogen Bonding
- The correct decreasing order of boiling points of hydrogen halides is:
- KCET - 2024
- Chemistry
- Hydrogen Bonding
- Which one of the following properties is generally not applicable to ionic hydrides?
- KCET - 2024
- Chemistry
- Hydrogen Bonding
- Select the compound from the following that will show intramolecular hydrogen bonding.
- JEE Main - 2024
- Chemistry
- Hydrogen Bonding
- Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : PH3 has lower boiling point than NH3.
Reason (R) : In liquid state NH3 molecules are associated through vander waal’s forces, but PH3 molecules are associated through hydrogen bonding.
In the light of the above statements.
Choose the most appropriate answer from the options given below:- JEE Main - 2024
- Chemistry
- Hydrogen Bonding
- Consider the following reactions
The number of protons that do not involve in hydrogen bonding in the product B is______.- JEE Main - 2024
- Chemistry
- Hydrogen Bonding
Questions Asked in JEE Main exam
- In a group of 3 girls and 4 boys, there are two boys \( B_1 \) and \( B_2 \). The number of ways in which these girls and boys can stand in a queue such that all the girls stand together, all the boys stand together, but \( B_1 \) and \( B_2 \) are not adjacent to each other, is:
- JEE Main - 2025
- Permutations
For the AC circuit shown in the figure, $ R = 100 \, \text{k}\Omega $ and $ C = 100 \, \text{pF} $, and the phase difference between $ V_{\text{in}} $ and $ (V_B - V_A) $ is 90°. The input signal frequency is $ 10^x $ rad/sec, where $ x $ is:
- JEE Main - 2025
- AC Circuits
Two parabolas have the same focus $(4, 3)$ and their directrices are the $x$-axis and the $y$-axis, respectively. If these parabolas intersect at the points $A$ and $B$, then $(AB)^2$ is equal to:
- JEE Main - 2025
- Parabola
A point particle of charge \( Q \) is located at \( P \) along the axis of an electric dipole 1 at a distance \( r \) as shown in the figure. The point \( P \) is also on the equatorial plane of a second electric dipole 2 at a distance \( r \). The dipoles are made of opposite charge \( q \) separated by a distance \( 2a \). For the charge particle at \( P \) not to experience any net force, which of the following correctly describes the situation?
- JEE Main - 2025
- Electrostatics and Work Done by Electric Field
- The value of \( (\sin 70^\circ)(\cot 10^\circ \cot 70^\circ - 1) \) is:
- JEE Main - 2025
- Trigonometric Identities
Concepts Used:
Hydrogen Bonding
Hydrogen bonding implies the formation of hydrogen bonds which are an attractive intermolecular force. An example of hydrogen bonding is the bond between the H atom and the O atom in water.
A special type of intermolecular attractive force arises only in the compounds having Hydrogen atoms bonded to an electronegative atom. This force is known as the Hydrogen bond. For instance, in water molecules, the hydrogen atom is bonded to a highly electronegative Oxygen.
The conditions for hydrogen bonding are:
- The molecule must contain a strongly electronegative atom that is bound to the hydrogen atom. The higher the electronegativity, the more polarized is the molecule.
- The electronegative atom must be small. The smaller the size, the greater the electrostatic magnetism.
Effects of Hydrogen Bonding on Elements:
Association: The molecules of carboxylic acids exist as dimer because of the hydrogen bonding. The molecular masses of such compounds are found to be double than those calculated from their simple formula.
Dissociation: In aqueous solution, HF dissociates and gives the difluoride ion instead of fluoride ion. This is due to hydrogen bonding in HF. The molecules of HCl, HBr, HI do not form a hydrogen bond. This explains the non-existence of compounds like KHCl2, KHBr2, KHI2.
Types of Hydrogen bonding
- Intramolecular Hydrogen bonding: When hydrogen bonding takes place between different molecules of the same or different compounds, it is called intermolecular hydrogen bonding.
- Intermolecular hydrogen bonding: The hydrogen bonding which takes place within a molecule itself is called intramolecular hydrogen bonding.
- Symmetrical Hydrogen bonding: The symmetric hydrogen bond is a type of a three-centre four-electron bond.