Chemistry M.C.Q [1M]

3. [Ni(CN)_4​​]⁻⁴, [Rh(CO)₂​(PPh₃​)₂​]⁺

2. Square planar

Explanation:

The geometry of [Ni(CN)_4​]²⁻ is square planar as shown in the image.

2. 109°28′

Explanation:

The angle between any two bonds to the central carbon atom in the methane molecule is 109°28′. The molecule of methane has a tetrahedral geometry.

3. 4

Explanation:

There are four stereoisomers are possible for the given coordination compound.

2. [Cu(NH₃​)₄​]SO_4​

Explanation:

Copper sulphate dissolves in ammonia due to the formation of [Cu(NH₃​)₄​]SO₄​.

CuSO₄ + 4NH₃ ​→ [Cu(NH₃​)_4​]SO₄​

[Cu(NH₃​)_4​]SO_4​ contains complex cation [Cu(NH₃​)₄​]²⁺.

2. Cu²⁺ and CN⁻

Explanation:

The coordinate covalent bond exists between the central metal and ligand. In K_2​[Cu(CN)₄​] ex the coordinate bond exists between Cu²⁺ and CN⁻.

3. Hybrid orbital formation

Explanation:

Hybrid formation was introduced to explain molecular structure when the other theories failed to correctly predict them.

4. Dodecacarbonyltrimanganese(0)

Explanation:

The correct IUPAC name of Mn₃​(CO)₁₂​ is dodecacarbonyltrimanganese(0). The central metal atom is a cobalt atom in zero oxidation state. The oxidation state is written in parenthesis.

Three such Mn atoms are present. Hence, the prefix tri is used. 12 carbonyl groups are present. Hence, the prefix dodeca is used.

2. +3

Explanation:

Oxidation state of chlorine Cl is −1.

Let the oxidation number of gold Au be x.

∴ x + 4 × (−1) = −1
⟹ x = +3
Thus oxidation number of gold is +3.

3. Ag

Explanation:

The developed photography film is due to Ag.

The treatment of the exposed photgraphic film with reducing agent is called developing of the film.

A developer is usually an alkaline solution of hydroquinone or alkaline solution of pyrogallol.

The pairs activated by light are reduced to deposit more of black silver.

4. [Cr(H₂O)₆]Cl₃

Explanation:

One mol of AgCl is precipitated by one mole of Cl^- ion, therefore three moles of AgCl would get precipitared by three moles of chloride ions, Cl^- and, in this case 3Cl^- are present in ionization sphere (i.e. outside the coordination sphere) in complex at (iv), therefore when 1mol of it is treated with excess of this complex 3mols of AgCl is precipitated. This satisfies the formula of the complex at (iv).

2. Calcium

Explanation:

In chlorophyll the central ion is magnesium, and the large organic molecule is a porphyrin. The porphyrin contains four nitrogen atoms that form bonds to magnesium in a square planar arrangement. There are several forms of chlorophyll.

So, an element not present in chlorophyll is calcium.

3. Potassium ferrocyanide

Explanation:

Only 'Potassium ferrocyanide' (i.e. [Fe(CN)₅​] ) shows properties of coordination compound.

When it gets dissolve they do not form simple ion like Fe⁺² or CN⁻, but instead their complex ions remain intact.

whereas carnallite (i.e. KMgCl₃​ ), Gypsum (i.e. CaSO₄​) and Ferrous ammonium sulphate (i.e. (NH₄​)_2​Fe(SO_4​)_2​ ) they dissovle and give simple ions.

1. Capped octahedral

Explanation:

2. Diaquatetrafluoroferrate(III) ion

Explanation:

In [FeF₄​(OH₂​)₂​]⁻ the oxidation state of iron is +3 so correct IUPAC name is diaquatetrafluoroferrate(III) ion.

4. Mononuclear

Explanation:

Iron carbonyl, Fe(CO)₅​ is mononuclear. In Fe(CO)₅​, one Fe atom is surrounded by 5 CO ligands. Mononuclear complexes are those complexes in which one metal atom/ion is surrounded by ligands.

4. Fe₄​[Fe(CN)₆​]₃

Explanation:

Ferric ferrocyanide / Potassium ferrocyanide / Sodium ferrocyanide is prussian blue. 

Fe₄​[Fe(CN)₆​]₃

1. Two cis and one trans

Explanation:

Square planar complex of the type MAXBL (where A, B, X, and L are unidentate ligands) shows two cis and one trans isomer as shown in the image.

2. Two types of valencies

Explanation:

According to Werner’s theory of valence, transition metals has two valencies are primary valencies and secondary valency.

The primary valency relates to the oxidation state and the secondary valency relates to the coordination number or it is the number of ligands attached to metal ions.

2. [Co(NH)₃​(NO₂​)₃​]

3. Different from the properties of its constituents

Explanation:

A compound is a substance formed when two or more chemical elements are chemically bonded together. The elements in any compound are always present in fixed ratios. 

Example: Pure methane is a compound made from two elements - carbon and hydrogen. The ration of hydrogen to carbon in methane is always 4:1. The properties of a compound are different from the properties of its constituents.

1. 8 and 4

Explanation:

Calcium fluoride crystallizes in a Face-Centered Cubic unit cell (FCC) having an edge length of 5.463 Angstroms.

The cell is displayed here with calcium cations (in blue) defining FCC lattice sites, and fluoride anions (in green) occupying all tetrahedral sites.

Fluoride anions have 4 neighbors of opposite charge arranged at vertices of an tetrahedron. Calcium cations have EIGHT neighbors of opposite charge arrange at corners that outline a smaller cube.

So the Ca: F coordination ratio is 8 : 4 or 2 : 1.

In 4CaF₂​ the the co ordination number of Ca⁺² is 8 F⁻ is 4.

1. [Cr(H_2​O)₅​Br]SO_4​

Explanation:

Among the following coordination compounds, the one giving a white precipitate with BaCl₂​ solution is [Cr(H_2​O)₅​Br]SO₄​.

It dissociates in aqueous solution to give sulphate ions. Sulphate ions react with barium chloride to form a white precipitate of barium sulphate.

4. K₃​[Cu(CN)₄​]

Explanation:

When excess of KCN is added to an aqueous solution of CuSO₄​ then-

Initially, cupric cyanide is formed, Cu(CN)₂​.

CuSO₄​ + 2KCN → K₂​CO₄ ​+ Cu(CN)_2​

Cupric Cyanide will decompose to produce cuprous cyanide,Cu₂​(CN)₂​.

2Cu(CN)₂ ​→ 2Cu₂​(CN)_2​ + 2(CN)

Cuprous cyanide reacts with an excess of KCN to form a complex, K₃​[Cu(CN)_4​], which is a stable complex.

CuCN + 3Ka → K₃​[Cu(CN)_4​].

4. Fe₂​(SO₄​)_3​

Explanation:

[Fe(CN)₆​]³⁻ and [Fe(CN)₆​]⁴⁻​ are complex ions.

They retain their identity in the solution.

Hence, they will not give Fe³⁺ ions in the solution.

NH₄​(SO₄​)₂​.FeSO₄​.6H₂​O is a double salt.

In the solution, it breaks into individual ions, but it will give Fe²⁺ ions in the solution.

Similarly, Fe₂​(SO₄​)_3​​ also breaks into individual ions.

Hence, they will give Fe³⁺ ions in the solution.

3. Diamminechloridonitrito-N-platinum (II).

Explanation:

In this case both the central atom as well as ligands are present in the coordination sphere. The legands are named first in alphabetical order before the name of central atom or ion. Names of the anionic ligands end with suffix '-o'. The name of the central metal atom is written at the end along with its oxidation state in Roman numeral, which is (II) for the central metal atom "platinum". Note the "chlorido" is preferred term/ name over chloro for chloride ion as a ligand as per modern trend.

2. 3

Explanation:

Loss of water on treatment with sulfuric acid indicates presence of water molecule in the ionization sphere.

Yellow precipitate of AgI on treatment with silver nitrate indicates presence of the iodide ion in the ionization sphere.

Thus the complex is [Co(en)₂​Cl₂​](H₂​O)I.

Two geometrical isomers cis and trans are possible.

Cis isomer is optically active and exists in d and l forms.

Trans isomer is optically inactive.

Thus total three steroisomers are possible.

2. 2_px​ and 2_py​ orbitals of carbon can be hybridized to yield two new more stable orbitals.

Explanation:

2_px​ & 2_py​ orbitals of Carbon cannot be hybridized to yield 2 more stable orbitals. This is because hybridization takes place between orbitals of different atoms thus the statement of option B is incorrect.

1. [MnCl₆]^3-

3. [CoF₆]^3-

Explanation:

Outer orbital complex or high spin complex Orbitals of Co³⁺ ion:

Again, fluoride ion is a weak field ligand. It cannot cause the pairing of the 3d electrons. As a result, the Co³⁺ ion will undergo sp³d² hybridization sp³d². Hybridized orbitals of Co³⁺ ion are:

Similarly, [MnCl₆]^3- is also outer orbital complex or high spin complex. Magnetic propertyparamagnetic due to presence of unpaired electrons in it.(The number. of unpaired electrons = 4)

2. d - d

Explanation:

Transition metals are coloured due to the d-d electronic transition.It's a transition where an electron jumps from one d orbital to another. Normally these are degenerate (the d orbitals have the same energy), but under some conditions, such as the presense of ligands, the degeneracy can be removed so that there is a specific energy (and therefore wavelength) associated with these transitions.

These sorts of transitions sometimes have energies located in the visible band, and it's one reason transition metal ions (and complex ions in particular) tend to be highly colored.

4. [Cr(SCN)_2​(NH₃)₄​]⁺

Explanation:

[Cr(SCN)_2​(NH₃)₄​]⁺ shows maximum number of isomers. It shows geometrical (cis trans) isomerism as well as linkage isomerism. SCN⁻ is ambidentate ligand and can coordinate through either S or N atom.

1. Geometrical and ionization

Explanation:

The octahedral complex [Co(NH₃​)_4​Br₂​]Cl exhibits geometrical as well as ionization isomerism.

The geometrical isomers are cis and trans isomers.

The ionization isomers are [Co(NH₃​)₄​Br₂​]Cland[Co(NH₃​)₄​Cl]Br₂​.

1. [Pt(NH₃​)₂​Br₂​Cl₂​]

Explanation:

In a complex compound, the neutral ligand is written first followed by an anionic ligand. But if there are more than one anionic ligand then their name is written in alphabetical order thus bromo is written first then chloro.

3. Negative ions

Explanation:

The primary or principal valency; this is the ionisable valency.

A metal always gives electron and becomes positively charged that can be neutralized by bonding with negative ion only. In a coordination compound, the number of negative ions needed to satisfy the charge on the central metal ion is it's primary valency.

4. Octahedral geometry

Explanation:

2. 3

Explanation:

Total number of stereo isomers of [Co(acac)₂​BrCl]⁻ are 3 i.e. cis, trans, optical.

1. Linkage isomers.

Explanation:

Linkage isomerism arises in a coordination compound containing ambidentate ligand. A simple example is provided by complexes containing the thiocyanate ligand, NCS-, which may bind through the nitrogen to give M-NCS or through sulphur to give M-SCN.

1. Fe₃​[Fe(CN)₆​]_2​

Explanation:

Turnbull's blue is Fe₃​[Fe(CN)₆​]_2​.

The structure is as follows:

3. Antiknocking

Explanation:

Anti knocking compounds are the chemicals which reduce knocking for improving the quality of gasoline. example:- Tetraethyl lead (TEL).

1. [Mn(H₂​O)6​]²⁺

Explanation:

Mn²⁺ has d⁵ configuration, since H₂​O is weak ligand field, so it does not causes pairing of electrons and hence it has 5 unpaired electrons.

3. d-block elements

Explanation:

Since 'd' block elements have higher oxidation states and variable oxidation states and their tendency to form co-ordinate bonds due to presence of unpaired electrons, they form co-ordination complexes.

3. Tetrammine copper (II) sulphate.

Explanation:

Since 4 amino groups are present, it will be called as tetrammine.

Since copper(II) is the central metal, it will be tetrammine copper(II). Note that we can determine the oxidation number of copper by charge balance.

Now finally since sulphate is the counter ion, it's full name will be tetrammine copper(II) sulphate.

2. [Cr(NH₃​)₅​][Co(CN)₅​]

Explanation:

Co-ordination isomerism is a form of structural isomerism in which the composition of the complexion varies. In a coordination isomer, the total ratio ligand to metal remains the same, but the ligand attached to specific metal ion change. In B option ratio of metal to the ligand is the same and they can exchange their ligands (NH_3​,CN).

2. Half field d-orbital

Explanation:

Fe³⁺ = 1s²2s²2p⁶3s²3p⁶3d⁵

d orbital is half filled.So ferric ion is stable.