Valence Bond Theory

Ammonia forms the complex ion  ${[\text{Cu}{({\text{NH}}_{\text{3}})}_{\text{4}}]}^{\text{2}+}$  with copper ions in alkaline solution but not in acidic solution. The probable reason for this is:

How many EDTA (ethylene diaminetetracetic acid) molecules are required to make an octahedral complex  ${\text{Ca}}^{\text{2}+}$  ion?

Nickel $(\mathrm{Z} = 28)$ combines with a uninegative monodentate ligand ${\mathrm{X}}^{-}$ to form a paramagnetic complex $[{\mathrm{NiX}}_4{]}^{2–}$. The number of unpaired electron/s in nickel and geometry of this complex ion are respectively _____.

The observed magnetic moment of the complex $\left[\mathrm{Mn}\right(\mathrm{NCS}{)}_6){]}^{\mathrm{x}-}$ is $6.06 \mathrm{BM}$. The numerical value of $\mathrm{x}$ is

The magnetic moment is measured in Bohr Magneton (BM). Spin only magnetic moment of $\mathrm{Fe}$ in ${\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}$ and ${\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]}^{3-}$ complexes respectively is:

The ratio of spin-only magnetic moment values  ${\mathrm{\mu }}_{\mathrm{eff}}{\left[\mathrm{Cr}(\mathrm{CN}{)}_6\right]}^{3-}/{\mathrm{\mu }}_{\mathrm{eff}}{\left[\mathrm{Cr}\left({\mathrm{H}}_2\mathrm{O}\right)6\right]}^{3+}$ is _______

If ${\mathrm{Ni}}^{2+}$ is replaced by ${\mathrm{Pt}}^{2+}$ in the complex ${\left[{\mathrm{NiCl}}_2{\mathrm{Br}}_2\right]}^{2-}$, which of the following properties are expected to get changed?
A. Geometry
B. Geometrical isomerism
C. Optical isomerism
D. Magnetic properties

The octahedral diamagnetic low spin complex among the following is

Given below are two statements, one is labelled as Assertion $\mathrm{A}$ and the other is labelled as Reason $\mathrm{R}.$

Assertion A: The spin only magnetic moment value for ${\left[\mathrm{Fe}(\mathrm{CN}{)}_6\right]}^{3-}$ is $1.74 \mathrm{BM},$ whereas for [Fe(H2O)6]${\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}$ is $5.92 \mathrm{BM}.$

Reason B: In both complexes, $\mathrm{Fe}$ is present in $+3$ oxidation state.

In the light of the above statements, choose the correct answer from the options given below:

The correct order of the number of unpaired electrons in the given complexes is

(A) $\left[\mathrm{Fe}\right(\mathrm{CN}{)}_6{]}^{3-}$

(B) ${\left[{\mathrm{FeF}}_6\right]}^{3-}$

(C) ${\left[{\mathrm{CoF}}_6\right]}^{3-}$

(D) ${\left[\mathrm{Cr}( \mathrm{oxalate} {)}_3\right]}^{3-}$

(E) $\left[\mathrm{Ni}(\mathrm{CO}{)}_4\right]$

Choose the correct answer from the options given below:

The correct order of spin only magnetic moments for the following complex ions is

Which of the following complex is octahedral, diamagnetic and the most stable?

Match List-I with List-II

Choose the correct answer from the options given below:

Magnetic moment of ${\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]}^{-3}$ and ${\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{+3}$ respectively are:

Find the spin only magnetic momentum ratio for complexes $\left[\mathrm{Cr}\right(\mathrm{CN}{)}_6{]}^{-3} \& \left[\mathrm{Cr}\right({\mathrm{H}}_2\mathrm{O}{)}_6{]}^{+3}$.

For a metal ion magnetic moment is calculated to be $4.9 \mathrm{BM}$. Find the number of unpaired electron

Which of the following complex compound is diamagnetic and low spin?