Question

Statement 1: The number of unpaired electrons in the following ions:
$M{n}^{2+},C{r}^{3+},V^{3+}$ and $T{i}^{3+}$ are 5, 3, 2 and 1 respectively.
Statement 2: $V^{3+}$ has a magnetic moment $(8{)}^{\frac{1}{2}}BM$

• A. Statement 1 is true, statement 2 is true, statement 2 is the correct explanation for statement 1
• B. Statement 1 is true, statement 2 is true, statement 2 is not the correct explanation for statement 1
• C. Both statements are false
• D. Statement 1 is false, statement 2 is true

Answer 1

The correct option is B Statement 1 is true, statement 2 is true, statement 2 is not the correct explanation for statement 1

(1) The electronic configuration of
$M{n}^{2+}=\left[Ar\right]3d^5$
$C{r}^{3+}=\left[Ar\right]3d^3$
$V^{3+}=\left[Ar\right]3d^2$
$T{i}^{3+}=\left[Ar\right]3d^1$
So number of unpaired electrons in $M{n}^{2+},C{r}^{3+},V^{3+}andT{i}^{3+}$ are 5, 3, 2 and 1 respectively.
(2) The magnetic moment can be calculated by the formula, $\left[\right(n\left)\right(n+2){]}^{\frac{1}{2}}$, where n = number of unpaired electrons. Thus magnetic moment of $V^{3+}$ is $8^{\frac{1}{2}}BM$