JEE Mains · Chemistry · STD 12 - 4. d and f- block elements
The pair of metal ions that can give a spin-only magnetic moment of \(3.9\, BM\) for the complex \([M(H_2O)_6]Cl_2\) is
- A \(V^{2+}\) and \(Co^{2+}\)
- B \(V^{2+}\) and \(Fe^{2+}\)
- C \(Co^{2+}\) and \(Fe^{2+}\)
- D \(Cr^{2+}\) and \(Mn^{2+}\)
Answer & Solution
Correct Answer
(A) \(V^{2+}\) and \(Co^{2+}\)
Step-by-step Solution
Detailed explanation
\(H_2O\) is weak field ligand and magnetic moment \(=\) moment \(=\,\sqrt {n(n+2)} \,BM\) Solving for \('n'\) we get it as \(3;\) i.e., no. of unpaired electron \(=\,3\) \(F{e^{2 + }}\, = \,{t_{2g}}^4\,{e_g}^2\) \(C{o^{2 + }}\, = \,{t_{2g}}^5\,{e_g}^2\)…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Chemistry
- A student has been given a compound "x" of molecular formula - \(C _6 H _7 N\). 'x' is sparingly soluble in water. However, on addition of dilute mineral acid , 'x' becomes soluble in water. 'x' when treated with \(CHCl _3\) and KOH (alc.) 'y' is produced. 'y' has a specific unpleasant smell. On treatment with benzenesulphonyl chloride, '\(x\)' gives a compound '\(z\)' which is soluble in alkali. The number of different "H" atoms present in '\(z\)' is:-JEE Mains 2026 Medium
- Liquid \(‘M’\) and liquid \(‘N’\) form an ideal solution. The vapour pressures of pure liquids \(‘M’\) and \(‘N’\) are \(450\) and \(700\,mmHg,\) respectively at the same temperature. Then correct statement is:
( \(x_M =\) mole fraction of \(‘M’\) in solution; \(x_N =\) mole fraction of \(‘N’\) in solution;
\(y_M =\) mole fraction of \(‘M’\) in vapour phase; \(y_N =\) mole fraction of \(‘M’\) in vapour phase)JEE Mains 2019 Hard - The following structures are
JEE Mains 2026 Medium - The number of orbitals associated with quantum numbers \(n=5,\;m_s=+\frac 12\) isJEE Mains 2020 Medium
- Compound \(A\) is converted to \(B\) on reaction with \(\mathrm{CHCl}_{3}\) and \(\mathrm{KOH}\). The compound \(\mathrm{B}\) is toxic and can be decomposed by \(C.\) \(A, B\) and \(C\) respectively are :JEE Mains 2021 Easy
- \(\Delta_{\text {vap }} \mathrm{H}^{\ominus}\) for water is \(+40.49 \mathrm{~kJ} \mathrm{~mol}^{-1}\) at 1 bar and \(100^{\circ} \mathrm{C}\). Change in internal energy for this vapourisation under same condition is _______ \(\mathrm{kJ}\) \(\mathrm{mol}^{-1}\). (Integer answer) (Given \(\mathrm{R}=8.3 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}\) )JEE Mains 2024 Medium
More PYQs from JEE Mains
- Consider an arithmetic series and a geometric series having four initial terms from the set \(\{11,8,21,16,26,32,4\}\) If the last terms of these series are the maximum possible four digit numbers, then the number of common terms in these two series is equal to .......JEE Mains 2021 Medium
- Let \(a,b \in R,\left( {a \ne 0} \right)\). if the function \(f\) defined as \(f\left( x \right)\left\{ \begin{array}{l}
\frac{{2{x^2}}}{a}\,\,\,\,\,\,\,\,\,\,\,\,,\,\,\,\,\,0 \le x < 1\,\,\,\\
a\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,,\,\,\,\,\,1 \le x < \sqrt 2 \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\\
\frac{{2{b^2} - 4b}}{{{x^3}}}\,\,\,,\,\,\,\,\,\sqrt 2 \le x < \infty
\end{array} \right.\,\,\,\,\) is continuous in the interval \(\left[ {0,\infty } \right)\) , then an ordered pair \((a, b)\) isJEE Mains 2016 Hard - \(C_{60},\) an allotrope of carbon containsJEE Mains 2019 Hard
- For complete combustion of ethanol, \(C_2H_5OH_{(l)}+{3O_2} _{(g)} \rightarrow 2{CO_2} _{(g)}+3{H_2O}_{(l)}\) the amount of heat produced as measured in bomb calorimeter, is \(1364.47\, kJ\, mol^{-1}\) at \(25\,^oC.\) Assuming ideality the enthalpy of combustion, \(\Delta_CH,\) for the reaction will be : \((R = 8.314\,kJ \,mol^{-1})\) .....\(kJ\, mol^{-1}\)JEE Mains 2014 Hard
- The correct statements among \((a)\) to \((b)\) are: \((a)\) saline hydrides produce \(H_2\) gas when reacted with \(H_2O.\) \((b)\) reaction of \(LiAH_4\) with \(BF_3\) leads to \(B_2H_6.\) \((c)\) \(PH_3\) and \(CH_4\) are electron - rich and electron-precise hydrides, respectively. \((d)\) \(HF\) and \(CH_4\) are called as molecular hydrides.JEE Mains 2019 Hard
- A conducting circular loop of area \( 1.0 m^{2} \) is placed perpendicular to a magnetic field which varies as \( B = \sin(100 t) \) Tesla. If the resistance of the loop is 100 \( \Omega \), then the average thermal energy dissipated in the loop in one period is ___________ J.JEE Mains 2026 Medium