Why $\mathrm{E}^{\circ}$ values for $\mathrm{Mn}, \mathrm{Ni}$ and $\mathrm{Zn}$ are more negative than expected?
The more negative $\mathrm{E}^{\circ}$ values for $\mathrm{Mn}^{2+}$ and $\mathrm{Zn}^{2+}$ is due to half filled and fully filled configurations respectively. While large negative value of $\mathrm{Ni}^{2+}$ is due to highest negative hydration enthalpy.
Among $\mathrm{CrO}, \mathrm{Cr}_2 \mathrm{O}_3$ and $\mathrm{CrO}_3$, the sum of spin-only magnetic moment values of basic and amphoteric oxides is . . . . . . . . $10^{-2} \mathrm{BM}$ (nearest integer).
(Given atomic number of $\mathrm{Cr}$ is 24 )
Assertion : Transition metals are good catalysts.
Reason : $V_2O_5$ or $Pt$ is used in the preparation of $H_2SO_4$ by contact process.
Among $Co ^{3+}, Ti ^{2+}, V ^{2+}$ and $Cr ^{2+}$ ions, one if used as a reagent cannot liberate $H _{2}$ from dilute mineral acid solution, its spin-only magnetic moment in gaseous state is $......B.M$. (Nearest integer)
Which of the following has highest paramagnetic character
Metre scales are made-up of alloy