Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Radius of H+ is 1.5 × 10–3 pm
Reason (R) : H+ cannot exist independently
In the light of the above statements, write the detailed answer:
Assertion (A) : Radius of H+ is 1.5 × 10–3 pm
Reason (R) : H+ cannot exist independently
In the light of the above statements, write the detailed answer:
Solution and Explanation
Analysis of Assertion (A):
- The hydrogen ion (H+) is essentially a proton.
- Since a proton is a subatomic particle with an extremely small size, its radius is approximately 1.5 × 10–3 pm.
- Thus, the Assertion (A) is correct.
Analysis of Reason (R):
- H+ is a bare proton without any electrons. Due to its high charge density and extremely small size, it cannot exist independently in nature.
- Instead, it immediately associates with other atoms or molecules, typically forming complexes like H3O+ in aqueous solutions.
- Thus, the Reason (R) is also correct.
Conclusion:
Both the Assertion (A) and Reason (R) are correct. Furthermore, the Reason (R) correctly explains the Assertion (A). Therefore, the correct answer is:
Option A: Both A and R are true, and R is the correct explanation of A.
Top Questions on Hydrogen
- For hydrogen-like species, which of the following graphs provides the most appropriate representation of \( E \) vs \( Z \) plot for a constant \( n \)?
Consider the following data:
- Heat of formation of \( CO_2(g) \) = -393.5 kJ mol\(^{-1}\)
- Heat of formation of \( H_2O(l) \) = -286.0 kJ mol\(^{-1}\)
- Heat of combustion of benzene = -3267.0 kJ mol\(^{-1}\)
The heat of formation of benzene is ……… kJ mol\(^{-1}\) (Nearest integer).Which of the following is/are correct with respect to the energy of atomic orbitals of a hydrogen atom?
(A) \( 1s<2s<2p<3d<4s \)
(B) \( 1s<2s = 2p<3s = 3p \)
(C) \( 1s<2s<2p<3s<3p \)
(D) \( 1s<2s<4s<3d \)
Choose the correct answer from the options given below:An ideal gas undergoes a cyclic transformation starting from point A and coming back to the same point by tracing the path A→B→C→D→A as shown in the three cases below.
Choose the correct option regarding \(\Delta U\):- The ratio of magnitude of potential energy and kinetic energy for \(5^{th}\) excited state of hydrogen atom is
Questions Asked in JEE Main exam
Match List-I with List-II.
Choose the correct answer from the options given below :- JEE Main - 2025
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- Differential equations
- Marks obtained by all the students of class 12 are presented in a frequency distribution with classes of equal width. Let the median of this grouped data be 14 with median class interval 12-18 and median class frequency 12. If the number of students whose marks are less than 12 is 18, then the total number of students is:
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- Statistics
- Let the system of equations $ x + 5y - z = 1 $ $ 4x + 3y - 3z = 7 $ $ 24x + y + \lambda z = \mu $ where $ \lambda, \mu \in \mathbb{R} $, have infinitely many solutions. Then the number of the solutions of this system, if $x, y, z$ are integers and satisfy $7 \leq x + y + z \leq 77$, is:
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- Linear Systems and Determinants
- A force of 49 N acts tangentially at the highest point of a sphere (solid of mass 20 kg) kept on a rough horizontal plane. If the sphere rolls without slipping, then the acceleration of the center of the sphere is:
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- Quantum Mechanics
Concepts Used:
Dihydrogen
Dihydrogen is the homonuclear diatomic molecule built from two hydrogen atoms. This molecule characterizes a covalent bond between two hydrogen atoms, satisfying each of their required pair configurations.
Structure of Dihydrogen:
The dihydrogen molecule characterizes a single covalent bond between the two hydrogen atoms that comprise it. This molecule has a linear shape and is nonionic in nature. Each hydrogen atom comes up with one electron towards the covalent bond.
Properties of Dihydrogen:
- At Standard Temperature and Pressure (STP), dihydrogen exists in the gaseous state.
- The melting point of H2 is 13.99 Kelvin. Transforming this value to the celsius scale, the melting point of dihydrogen can be expressed as -259.16 degrees celsius.
- The boiling point correlated with dihydrogen corresponds to 20.271 on the Kelvins scale. Transforming this value into the celsius scale, the boiling point of H2 can be represented as -252.879 degrees celsius.
- The latent heat of fusion associated with the H2 molecule correlates to 0.117 kilojoules per mole.
- The latent heat of vaporization (also known as the enthalpy of vaporization) of dihydrogen is equivalent to 0.904 kilojoules per mole.