36 Questions
Solutions can be stabilized by addition of ______ in order to prevent hydrolysis.
acids
The reaction between Fe and S forms ______.
FeS
Sulphides of transition metals are usually ______ in colour.
black
In a disproportionation reaction, a species is simultaneously ______ and oxidized.
reduced
The manganate(VI) ion MnO42- is stable in ______ medium.
alkaline
The cuprous ion decomposes to give ______ metal and cupric ion Cu2+.
copper
Disproportionation is a type of ______ reaction.
redox
The reaction 3MnO42-(aq) + 4H+(aq) → 2MnO4-(aq) + MnO2(s) + 2H2O(l) is an example of ______.
disproportionation
Alloys of transition metals with non-transition metals such as ______ (copper-zinc) and bronze (copper-tin).
brass
The transition metals and their compounds are known for their ______ activity.
catalytic
The ability of the d-block metals to show variable ______ states enables the formation of unstable intermediate compounds.
oxidation
Transition metals also provide a suitable ______ for the reactions to occur.
surface
The d-block elements are important ______ in industry and biological systems.
catalysts
The alloys so formed are hard and have often high ______ points.
melting
D orbitals are filled before _____ orbitals in the same principal energy level
p
The _____ sphere is enclosed in brackets in formulas for complex species, and it includes the central metal ion plus the coordinated groups.
coordination
In coordination chemistry, the donor atom of a ligand is the atom in the ligand that _____ an electron pair with the metal.
shares
A coordinate covalent bond exists between _____ and CN- in the coordination compound K2[Cu(CN)4].
Cu2+
The oxidation number of the central metal atom in the coordination compound [Pt(NH3)3Cl]Cl is _____.
2+
There are _____ types of d orbital.
5
The element that exhibits highest number of valences is ______.
Ti
The element with the lowest atomization energy is ______.
Mn
The number of dative bonds to the central metal ion is its ______.
coordination number
The element that has an equal number of paired and unpaired electrons in the valence shell is ______.
Mn
The ion species that is susceptible to reduction is ______.
Cr6+
The compound in which chromium has one electron in the valence shell is ______.
K2Cr2O7
The most stable oxidation state of ______ is +2.
cobalt
The anhydride of manganic acid is ______.
Mn2O7
The higher oxidation states are exhibited when ns and (n-1)d-______ take part in bonding.
electrons
In the first transition series, ______ shows the maximum oxidation state of +7.
manganese
The highest oxidation state shown by any transition metal is ______.
+8
Ruthenium in second transition series and ______ in the third transition series show +8 oxidation state.
osmium
In general, the minimum oxidation state shown by a transition metal is equal to the number of ______-electrons.
ns
The maximum oxidation state shown by titanium is ______ (3d2 4s2).
+4
For chromium and copper, the lowest oxidation state is ______.
+1
The common oxidation states for the elements from Fe to Ni are ______ or +3.
+2
Study Notes
Oxidation States of Transition Metals
- The lower oxidation state is exhibited when ns electrons participate in bonding, and higher oxidation states are exhibited when ns and (n-1)d-electrons take part in bonding.
- The highest oxidation state of transition metals increases with the increase of atomic number, reaches a maximum in the middle, and then decreases.
- Ruthenium in the second transition series and osmium in the third transition series show +8 oxidation state.
Factors Affecting Oxidation States
- The minimum oxidation state shown by a transition metal is equal to the number of ns-electrons.
- Except for scandium, the +2 oxidation state is the most common in the first transition series, due to the loss of 4s-electrons.
- Chromium and copper have a lowest oxidation state of +1, due to their electronic configurations.
Disproportionation
- Intermediate oxidation states have a tendency to disproportionate in a specific type of redox reaction, where a species is simultaneously reduced and oxidized to form two types of products.
- Example: The disproportionation of potassium manganate compound K2MnO4 in acidic aqueous solution.
Alloys of Transition Metals
- The alloys formed by transition metals are hard and have high melting points.
- Ferrous alloys containing chromium, vanadium, tungsten, molybdenum, and manganese are used in the production of steels and stainless steel.
- Alloys of transition metals with non-transition metals, such as brass (copper-zinc) and bronze (copper-tin), are also formed.
Catalytic Activity
- Transition metals and their compounds are known for their catalytic activity, due to their ability to show variable oxidation states and provide a suitable surface for reactions to occur.
- They enable reactions to proceed faster by providing an alternative reaction pathway of lower activation energy.
Coordination Chemistry
- In coordination chemistry, the donor atom of a ligand is the atom in the ligand that shares an electron pair with the metal.
- The coordination sphere is enclosed in brackets in formulas for complex species and includes the central metal ion plus the coordinated groups.
Properties of Transition Metals
- Transition metals are characterized by hardness, high melting points, and catalytic activity.
- They exhibit variable oxidation states, which enable them to form alloys and compounds with other metals and non-metals.
This quiz covers the oxidation states of transition elements, including how ns electrons and (n-1)d-electrons participate in bonding, and how the highest oxidation state changes within the transition series.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
