Hydrogen peroxide acts both as an oxidising and as a reducing agent depending upon the nature of the reacting species. In which of the following cases $H_2O_2$ acts as a reducing agent in acid medium ?
- $MnO^{-}_{4}$
- $Cr_{2}O^{2-}_{7}$
- $SO^{2-}_{3}$
- $KI$
The Correct Option is A
Solution and Explanation
Top Questions on Bohr’s Model for Hydrogen Atom
- Consider an electron in the $ n = 3 $ orbit of a hydrogen-like atom with atomic number $ Z $. At absolute temperature $ T $, a neutron having thermal energy $ k_B T $ has the same de Broglie wavelength as that of this electron. If this temperature is given by $$ T = \frac{Z^2 h^2}{\alpha \pi^2 a_0^2 m_N k_B} $$ (where $ h $ is Planck’s constant, $ k_B $ is Boltzmann’s constant, $ m_N $ is the mass of the neutron, and $ a_0 $ is the Bohr radius), then the value of $ \alpha $ is ___.
- JEE Advanced - 2025
- Physics
- Bohr’s Model for Hydrogen Atom
- The wavelength of the first line in the Balmer series of hydrogen spectrum is 656 nm. What is the wavelength of the second line?
- CUET (UG) - 2025
- Chemistry
- Bohr’s Model for Hydrogen Atom
- According to Bohr's model of hydrogen atom, which of the following statement is incorrect?
- JEE Main - 2025
- Chemistry
- Bohr’s Model for Hydrogen Atom
Given below are two statements:
Statement (I) : The dimensions of Planck’s constant and angular momentum are same.
Statement (II) : In Bohr’s model, electron revolves around the nucleus in those orbits for which angular momentum is an integral multiple of Planck’s constant.
In the light of the above statements, choose the most appropriate answer from the options given below:- JEE Main - 2025
- Physics
- Bohr’s Model for Hydrogen Atom
- If \(a_0\) is denoted as the Bohr radius of the hydrogen atom, then what is the de-Broglie wavelength \( \lambda \) of the electron present in the second orbit of the hydrogen atom?
- JEE Main - 2025
- Chemistry
- Bohr’s Model for Hydrogen Atom
Questions Asked in JEE Main exam
Inductance of a coil with \(10^4\) turns is \(10\,\text{mH}\) and it is connected to a DC source of \(10\,\text{V}\) with internal resistance \(10\,\Omega\). The energy density in the inductor when the current reaches \( \left(\frac{1}{e}\right) \) of its maximum value is \[ \alpha \pi \times \frac{1}{e^2}\ \text{J m}^{-3}. \] The value of \( \alpha \) is _________.
\[ (\mu_0 = 4\pi \times 10^{-7}\ \text{TmA}^{-1}) \]- JEE Main - 2026
- Ray optics and optical instruments
A small block of mass \(m\) slides down from the top of a frictionless inclined surface, while the inclined plane is moving towards left with constant acceleration \(a_0\). The angle between the inclined plane and ground is \(\theta\) and its base length is \(L\). Assuming that initially the small block is at the top of the inclined plane, the time it takes to reach the lowest point of the inclined plane is _______.
- JEE Main - 2026
- General Physics
- Let \(\vec{a} = -\hat{i} + 2\hat{j} + 2\hat{k}\), \(\vec{b} = 8\hat{i} + 7\hat{j} - 3\hat{k}\) and \(\vec{c}\) be a vector such that \(\vec{a} \times \vec{c} = \vec{b}\). If \(\vec{c} \cdot (\hat{i}+\hat{j}+\hat{k}) = 4\), then \(|\vec{a}+\vec{c}|^2\) is equal to:
- JEE Main - 2026
- Vector Algebra
- Let \( \alpha \) and \( \beta \) respectively be the maximum and the minimum values of the function \( f(\theta) = 4\left(\sin^4\left(\frac{7\pi}{2} - \theta\right) + \sin^4(11\pi + \theta)\right) - 2\left(\sin^6\left(\frac{3\pi}{2} - \theta\right) + \sin^6(9\pi - \theta)\right) \). Then \( \alpha + 2\beta \) is equal to :
- JEE Main - 2026
- Statistics
- The crystal field splitting energy of $[Co(oxalate)_3]^3-$ complex is 'n' times that of the $[Cr(oxalate)_3]^3-$ complex. Here 'n' is_______ (Assume $\Delta_0 > P$)}
- JEE Main - 2026
- Solutions
Concepts Used:
Bohr's Model of Hydrogen Atom
Niels Bohr introduced the atomic Hydrogen model in 1913. He described it as a positively charged nucleus, comprised of protons and neutrons, surrounded by a negatively charged electron cloud. In the model, electrons orbit the nucleus in atomic shells. The atom is held together by electrostatic forces between the positive nucleus and negative surroundings.
Read More: Bohr's Model of Hydrogen Atom
Bohr's Theory of Hydrogen Atom and Hydrogen-like Atoms
A hydrogen-like atom consists of a tiny positively-charged nucleus and an electron revolving around the nucleus in a stable circular orbit.
Bohr's Radius:
If 'e,' 'm,' and 'v' be the charge, mass, and velocity of the electron respectively, 'r' be the radius of the orbit, and Z be the atomic number, the equation for the radii of the permitted orbits is given by r = n2 ｘr1, where 'n' is the principal quantum number, and r1 is the least allowed radius for a hydrogen atom, known as Bohr's radius having a value of 0.53 Å.
Limitations of the Bohr Model
The Bohr Model was an important step in the development of atomic theory. However, it has several limitations.
- Bohr’s model of the atom failed to explain the Zeeman Effect (effect of magnetic field on the spectra of atoms).
- It failed to explain the Stark effect (effect of electric field on the spectra of atoms).
- The spectra obtained from larger atoms weren’t explained.
- It violates the Heisenberg Uncertainty Principle.