Flexidentate Ligands

Q. How many EDTA molecules are required to make an octahedral complex with a $C{a}^{2+}$ ion?

1. 3
2. 1
3. 6
4. 2

Q. Select the incorrect order of stability :

1. $\left[Ni\right(dmg{)}_2]>[Ni(en{)}_2{]}^{2+}$
2. $\left[Fe\right(EDTA){]}^{2-}>[Fe\left(EDTA\right){]}^{-}$
3. $\left[Co\right(Ox{)}_3{]}^{3-}>\left[Co\right(N{H}_3{)}_6{]}^{3+}$
4. $\left[Co\right(N{H}_3{)}_6{]}^{3+}>\left[Co\right(H_{2}O{)}_6{]}^{3+}$

Q. When EDTA solution is added to $M{g}^{2+}$ solution, then which of the following statement is true

1. pH of the solution is decreased.
2. Four coordination sites of $M{g}^{2+}$ are occupied by EDTA and remaining two sites are occupied by water molecules.
3. All six coordination sites of $M{g}^{2+}$ are occupied.
4. Colourless $[Mg-EDTA{]}^{2-}$ chelate is formed.

Q. How many EDTA molecules are required to make an octahedral complex with a $C{a}^{2+}$ ion?

1. Six
2. Three
3. One
4. Two

Q. Out of the complexes ${\left[Fe\left(H_{2}O{)}_6\right)\right]}^{3+}$, ${\left[Fe{\left(CN\right)}_6\right]}^{3-}$, ${\left[Fe{\left(C_2{O}_4\right)}_3\right]}^{3-}$ and ${\left[Fe{\left(Cl\right)}_6\right]}^{3-}$, the most stable one is:

1. ${\left[Fe\left(H_{2}O{)}_6\right)\right]}^{3+}$
2. ${\left[Fe{\left(CN\right)}_6\right]}^{3-}$
3. ${\left[Fe{\left(C_2{O}_4\right)}_3\right]}^{3-}$
4. ${\left[Fe{\left(Cl\right)}_6\right]}^{3-}$

Q. The coordination of Pt in the complex ion $\left[Pt\right(en{)}_{2}C{l}_2{]}^{2+}$ is:

1. 3
2. 4
3. 5
4. 6

Q. Which of the following can act as both monodentate and bidentate ligand?

1. None of the above
2. $H_{2}O$
3. $C{N}^{-}$
4. $S{O}_4^{2-}$

Q. Assertion :$K_2\left[Ni\right(EDTA\left)\right]$ is more stable than $K_3\left[Al\right(C_2{O}_4{)}_3]$. Reason: Ni is a transition element while Al is a non - transition element

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Several octahedral complexes are possible from combinations of $C{o}^{3+},C{l}^{-}$ and $N{H}_3$. The correct statement(s) regarding the octahedral coordination entities having the formula .$\left[Co\right(N{H}_3{)}_{n}C{l}_{6-n}{]}^{(n-3)+}$ with $n\ge 3$, is/ are_____________.

1. At most six octahedral complexes are possible
2. One of the complexes is homoleptic
3. All the complexes are paramagnetic
4. Some of the complexes dissociate in water to give $C{o}^{3+}$ and $C{l}^{-}$ ions

Q. What is the cordination number of $Fe$ in $\left[Fe\right(C_2{O}_4{)}_3{]}^{3-}$?

Q. Which of the following statements is not correct regarding $M{n}_3{O}_4$?

1. It is black in colour and the most stable oxide at high temperature
2. It has spinel structure
3. It contains both $Mn(+II)\text{and}Mn(+III),\text{i.e}.,\left(M{n}^{II}M{n}_2^{III}{O}_4\right)$
4. $O$ atoms are closed packed with $Mn(+III)$ in tetrahedral holes and $Mn(+II)$ in octahedral holes
   

Q. Select outer $d$-complexes :
I : $\left[Fe\right(CN{)}_6{]}^{3-}$ II : $\left[Fe\right(H_{2}O{)}_6{]}^{3+}$ III : $[Co{F}_5{]}^{3-}$

1. II, III
2. I, III
3. I, II
4. I, II, III

Q. In the compound Lithium tetrahydrido-aluminate(III), the ligand is:

1. $H$
2. $A{l}^{+}$
3. $H^{-}$
4. none of the above

Q. Regarding complex formation by $2^{nd}$ group metals, the correct statement(s) is/are:

1. $B{e}^{2+}$ forms complexes with oxalic acid, catechol to give tetrahedral complexes.
2. In chlorophyll, 2 N-atoms of porphyrin ring are bonded to the magnesium atom in the complex.
3. Beryllium forms complexes only with halide ligands.
4. $M{g}^{2+}$ and $C{a}^{2+}$ can form complexes with EDTA, while $B{e}^{2+}$ cannot.

Q. In CsCl structure, the coordination number of $C{s}^{+}$ is

1. Equal to that of $C{l}^{-}$, that is 6
2. Equal to that of $C{l}^{-}$, that is 8
3. Not equal to that of $C{l}^{-}$, that is 6
4. Not equal to that of $C{l}^{-}$, that is 8

Q. Which of the following can act as both monodentate and bidentate ligand?

Q. Which of the following can act as both monodentate and bidentate ligand?

1. $H_{2}O$
2. None of the above
3. $C{N}^{-}$
4. $S{O}_4^{2-}$

Q. $C{o}^{2+}(aq.)+SC{N}^{-}(aq.)\to Complex\left(X\right)$
$N{i}^{2+}(aq.)+dimethylglyoxime\stackrel{N{H}_{4}OH}{\to }Complex\left(Y\right)$
The coordination number of cobalt and nickel in both the complexes (X) and (Y) is four. Select the correct statement for the complexes (X) and (Y).

1. (X) is paramagnetic with two unpaired electrons.
2. (Y) is diamagnetic and shows intermolecular H-bonding.
3. (X) and (Y) both are diamagnetic.
4. (X) is paramagnetic with three unpaired electrons and (Y) is diamagnetic.