Out of KMnO4 and K2MnO4, which one is paramagnetic and why?
Show Hint
Solution and Explanation
To determine which compound is paramagnetic, we need to examine the oxidation state of manganese and the electron configuration of the manganese ion in each compound. - KMnO$_4$ (Potassium permanganate): In KMnO$_4$, the manganese ion exists in the \(+7\) oxidation state (Mn$^{7+}$). The electron configuration of Mn$^{7+}$ is \( 3d^0 4s^0 \), meaning that all d-orbitals are empty. Since there are no unpaired electrons, KMnO$_4$ is diamagnetic.
- K$_2$MnO$_4$ (Potassium manganate): In K$_2$MnO$_4$, the manganese ion exists in the \(+6\) oxidation state (Mn$^{6+}$). The electron configuration of Mn$^{6+}$ is \( 3d^1 4s^0 \), meaning there is one unpaired electron in the d-orbital. Since there is at least one unpaired electron, K$_2$MnO$_4$ is paramagnetic.
Step 1: Examine the oxidation state of manganese in each compound.
Step 2: Check the number of unpaired electrons in the electron configuration of the manganese ion.
Top CBSE CLASS XII Chemistry Questions
- ${AgNO_3}$ does not decompose where :
- Azeotropic mixture of water and HCl boils at 381.5 K. By distilling the mixture it is possible to obtain
Write IUPAC names of the following compounds and classify them into primary, secondary and tertiary amines.
(i) (CH3 )2CHNH2 (ii) CH3 (CH2 )2NH2 (iii) CH3NHCH(CH3 )2
(iv) (CH3 )3CNH2 (v) C6H5NHCH3 (vi) (CH3CH2 )2NCH3 (vii) m–BrC6H4NH2
Give one chemical test to distinguish between the following pairs of compounds.
(i) Methylamine and dimethylamine
(ii) Secondary and tertiary amines
(iii) Ethylamine and aniline
(iv) Aniline and benzylamine
(v) Aniline and N-methylanilineAccount for the following:
(i) pKb of aniline is more than that of methylamine.
(ii) Ethylamine is soluble in water whereas aniline is not.
(iii) Methylamine in water reacts with ferric chloride to precipitate hydrated ferric oxide.
(iv) Although amino group is o– and p– directing in aromatic electrophilic substitution reactions, aniline on nitration gives a substantial amount of m-nitroaniline.
(v) Aniline does not undergo Friedel-Crafts reaction.
(vi) Diazonium salts of aromatic amines are more stable than those of aliphatic amines. (vii) Gabriel phthalimide synthesis is preferred for synthesising primary amines.
Top CBSE CLASS XII Redox Reactions Questions
- Acidified KMnO$_4$ oxidizes sulphite to:
Acidified \(KMnO_4\) oxidizes sulphite to:
Complete and balance the following chemical equations: (a) \[ 2MnO_4^-(aq) + 10I^-(aq) + 16H^+(aq) \rightarrow \] (b) \[ Cr_2O_7^{2-}(aq) + 6Fe^{2+}(aq) + 14H^+(aq) \rightarrow \]
Which element is a strong reducing agent in +2 oxidation state and why?
Convert Propanoic acid to Ethane
Top CBSE CLASS XII Questions
- 2, b, c are in A.P. and the range of determinant $\begin{vmatrix}1&1&1\\ 2&b&c\\ 4&b^{2}&c^{2}\end{vmatrix}$ is [2, 16]. Then find range of c is
- A boy of mass 50 kg is standing at one end of a, boat of length 9 m and mass 400 kg. He runs to the other, end. The distance through which the centre of mass of the boat boy system moves is
- A capillary tube of radius r is dipped inside a large vessel of water. The mass of water raised above water level is M. If the radius of capillary is doubled, the mass of water inside capillary will be
- A circular disc is rotating about its own axis. An external opposing torque 0.02 Nm is applied on the disc by which it comes rest in 5 seconds. The initial angular momentum of disc is
- A circular disc is rotating about its own axis at uniform angular velocity \(\omega.\) The disc is subjected to uniform angular retardation by which its angular velocity is decreased to \(\frac {\omega}{2}\) during 120 rotations. The number of rotations further made by it before coming to rest is