Chemistry 9701 · AS & A Level
Chemistry of transition elements
100 practice questions on Chemistry of transition elements, with worked solutions and instant marking.
Complete the electronic configurations of the species below. $\text{Co}\ \ [\text{Ar}]\ \ldots$ $\text{Co}^{2+}\ \ [\text{Ar}]\ \ldots$
Feb/March 2016
Sketch the form of one $d$ orbital.
Feb/March 2017
Complete the electronic configuration for a chromium atom. $1s^2 2s^2 2p^6 3s^2$ \dots
Feb/March 2018
Complete the electronic configuration for a copper atom. $$1s^22s^22p^6\ \ldots$$
Feb/March 2019
Iron is a transition element in the fourth period. It forms compounds that contain the ions $\text{Fe}^{2+}$ and $\text{Fe}^{3+}$.
Feb/March 2020
The oxidation states of cobalt most often encountered are $+2$ and $+3$.
Feb/March 2021
Transition elements can make stable complexes with a wide variety of molecules and ions.
Feb/March 2021
Carboplatin and satraplatin are anticancer drugs used instead of cisplatin.
Feb/March 2021
Titanium is a transition element in Period 4. In minerals, it is most often encountered as $\text{TiO}_2$.
Feb/March 2022
Vanadium belongs to the transition elements in Period 4 of the Periodic Table.
Feb/March 2023
Iron is a transition metal placed in Group 8 of the Periodic Table.
Feb/March 2024
Ruthenium and osmium are transition metals positioned beneath iron in Group 8 of the Periodic Table.
Feb/March 2024
$\text{Fe}^{2+}$ and $\text{Fe}^{3+}$ ions can make a range of complexes with different species.
Feb/March 2025
Maleic anhydride is an unsaturated cyclic compound that is used to make several polymers. It can be converted into maleic acid and tartaric acid, as shown in Fig. 6.1.
Feb/March 2025
Give the electronic configurations for the $\text{Cr}^{3+}$ and $\text{Mn}^{2+}$ ions. $\text{Cr}^{3+}$: $1s^2 2s^2 2p^6 \ldots$ $\text{Mn}^{2+}$: $1s^2 2s^2 2p^6 \ldots$
May/June 2010
What is meant by density of a substance?
May/June 2013
Suggest why transition elements display variable oxidation states in their compounds whereas s-block elements like calcium do not.
May/June 2013
What does the density of a substance mean?
May/June 2013
Transition element ions form complexes when they react with ligands.
May/June 2014
In the diagrams below, indicate the outer electron arrangements of the atoms and ions shown. (Use the symbol $\uparrow\downarrow$ to show two electrons paired in one orbital.)
May/June 2014
Transition-element ions make complexes when they combine with ligands.
May/June 2014
Transition elements and their compounds are commonly used as catalysts. What is the identity of, and what is the oxidation number of, the element contained in the catalyst used in the Contact process?
May/June 2015
Complete these electronic configurations: cobalt atom, $\text{Co}$: $1s^22s^22p^6\,\ldots$ ; cobalt(II) ion, $\text{Co}^{2+}$: $1s^22s^22p^6\,\ldots$.
May/June 2016
Chromyl chloride, $\text{CrO}_2\text{Cl}_2$, is made by warming a mixture of potassium dichromate(VI) and potassium chloride with concentrated sulfuric acid. $\text{K}_2\text{Cr}_2\text{O}_7 + 4\text{KCl} + 3\text{H}_2\text{SO}_4 \rightarrow 2\text{CrO}_2\text{Cl}_2 + 3\text{K}_2\text{SO}_4 + 3\text{H}_2\text{O}$.
May/June 2016
Complete the electronic configuration for the iron atom. $\text{Fe }\; 1s^2\,2s^2\,2p^6\,\ldots$
May/June 2016
Cadmium ions can make complexes with primary amines as well as with 1,2-diaminoethane. $ \text{Cd}^{2+}(aq) + 4\text{CH}_3\text{NH}_2(aq) \rightleftharpoons [\text{Cd}(\text{CH}_3\text{NH}_2)_4]^{2+}(aq) \qquad K_{\text{stab}} = 3.6 \times 10^6 \; \text{(equilibrium I)} $ $ \text{Cd}^{2+}(aq) + 2\text{H}_2\text{NCH}_2\text{CH}_2\text{NH}_2(aq) \rightleftharpoons [\text{Cd}(\text{H}_2\text{NCH}_2\text{CH}_2\text{NH}_2)_2]^{2+}(aq) \qquad K_{\text{stab}} = 4.2 \times 10^{10} \; \text{(equilibrium II)} $
May/June 2016
Complete these electronic configurations: cobalt atom, $\text{Co}$: $1s^22s^22p^6\ldots$ ; cobalt(II) ion, $\text{Co}^{2+}$: $1s^22s^22p^6\ldots$.
May/June 2016
Several isomers with the formula $\text{Cr(H}_2\text{O)}_6\text{Cl}_3$ are known. Their overall formula is $[\text{Cr(H}_2\text{O)}_{6-n}\text{Cl}_n]\text{Cl}_{3-n} \cdot n\text{H}_2\text{O}$. In each case, a Cr(III) ion is six-co-ordinated in an octahedral complex. Water molecules that are not bonded directly to the Cr atom remain in the crystal lattice as water of crystallisation. The Cr-Cl bond is difficult to break, so chloride bonded to the Cr(III) ion in the complex does not react. $1.00\,\text{g}$ samples of three isomers, $\text{A}$, $\text{B}$ and $\text{C}$, were dissolved separately in water. An excess of $\text{AgNO}_3(aq)$ was then added to each sample and the mass of $\text{AgCl}(s)$ formed was measured. $\text{Ag}^+(aq) + \text{Cl}^-(aq) \rightarrow \text{AgCl}(s)$
May/June 2017
What do the terms bidentate and ligand mean?
May/June 2017
Passing air through separate aqueous mixtures of CoCl$_2$, NH$_4$Cl and NH$_3$ gives a range of complex ions with the general formula $[\text{Co(NH}_3)_6$-$_n\text{Cl}_n]^{3-n}$.
May/June 2017
Copper, with atomic number $29$, is a transition element.
May/June 2018
Cobalt is classed as a transition element and has atomic number 27. It can form ions with charges of $+2$ and $+3$, and both ions are able to form complexes.
May/June 2018
Copper is classified as a transition element and has atomic number $29$.
May/June 2018
Blue aqueous copper(II) salt solutions contain the $[\text{Cu(H}_2\text{O)}_6]^{2+}$ complex, and separate samples of this blue solution are treated with aqueous sodium hydroxide and with concentrated hydrochloric acid.
May/June 2019
The diagrams show the shapes of several atomic orbitals. Name the orbital type, $s$, $p$, or $d$.
May/June 2019
Complete the electronic configuration of the copper(II) ion: $1s^2 2s^2 2p^6 \; \ldots$
May/June 2019
Draw the outline of a $d$ orbital.
May/June 2019
In aqueous solution, copper(II) salts contain the blue [Cu(H2O)6]2+ complex ion. Separate samples of this blue solution are then treated with aqueous sodium hydroxide and with concentrated hydrochloric acid.
May/June 2019
Some atomic orbitals are shown as sketches of their shapes. Identify whether each orbital is $s$, $p$ or $d$.
May/June 2019
The aqueous cobalt(II) solution contains the complex ion $[\text{Co(H}_2\text{O)}_6]^{2+}$.
May/June 2020
EDTA$^{4-}$ is an example of a polydentate ligand.
May/June 2020
Write the electronic configuration for an isolated gaseous nickel(II) ion, $\text{Ni}^{2+}$.
May/June 2020
An aqueous cobalt(II) solution contains the $[\text{Co(H}_2\text{O)}_6]^{2+}$ complex ion.
May/June 2020
Element $Q$ has the electronic configuration $[\text{Ar}]\,3d^2\,4s^2$. Predict the oxidation states that are likely for element $Q$ in compounds.
May/June 2020
Explain why chromium complexes show colour.
May/June 2021
Define what is meant by transition element.
May/June 2021
Separate samples of $[\text{Cu}(\text{H}_2\text{O})_6]^{2+}$ are each treated with excess aqueous sodium hydroxide, or alternatively with excess aqueous ammonia.
May/June 2021
An aqueous chromium(III) solution contains the green $[\text{Cr}(\text{H}_2\text{O})_6]^{3+}$ complex ion.
May/June 2021
Explain the reason chromium complexes are coloured.
May/June 2021
Separate samples of $[\text{Cu(H}_2\text{O})_6]^{2+}$ are each treated with excess aqueous sodium hydroxide or excess aqueous ammonia.
May/June 2021
Define the term transition element.
May/June 2022
The $3d$ orbitals in an isolated $\text{Fe}^{2+}$ ion are degenerate. Finish the diagram to illustrate how the $3d$ orbital energy levels split in an isolated $\text{Fe}^{2+}$ ion and when $\text{Fe}^{2+}$ forms an octahedral complex.
May/June 2022
Explain why transition elements exhibit variable oxidation states.
May/June 2022
What is meant by a transition element?
May/June 2022
The $3d$ orbitals of an isolated $\text{Fe}^{2+}$ ion are degenerate. Finish the diagram to illustrate how the $3d$ orbital energy levels split first in an isolated $\text{Fe}^{2+}$ ion and then when $\text{Fe}^{2+}$ forms an octahedral complex.
May/June 2022
Some transition element complexes are capable of stereoisomerism. State two kinds of stereoisomerism displayed by transition element complexes.
May/June 2023
State any two common chemical properties of a transition element.
May/June 2023
Some transition element complexes are capable of stereoisomerism. State two kinds of stereoisomerism shown by transition element complexes.
May/June 2023
Define transition element clearly.
May/June 2024
Explain why transition elements show variable oxidation states.
May/June 2024
In the Haber process, the two gaseous reactants must react in the presence of a catalyst made from a transition element. State the metal and the mole ratio in which the gases combine?
May/June 2025
Copper is classed as a transition element.
May/June 2025
With the monodentate ligand, $\text{CN}^-$, iron forms complex ions.
May/June 2025
Dissolving cobalt(II) sulfate, $\text{CoSO}_4$, in distilled water produces solution A. Figure 2.1 presents some of the reactions of solution A.
May/June 2025
Iron is able to form complex ions with the monodentate ligand CN$^-$.
May/June 2025
What does the term ligand mean in transition element chemistry?
Oct/Nov 2010
What does the term ligand mean in transition element chemistry?
Oct/Nov 2010
The usual oxides of tin and lead are $\text{SnO}$, $\text{SnO}_2$, $\text{PbO}$ and $\text{PbO}_2$. Two broad patterns for Group IV oxides are: • As the elements become more metallic down the Group, their oxides show greater basic character. • Oxides with the elements in higher oxidation states are more acidic than the oxides with the elements in lower oxidation states.
Oct/Nov 2010
In the human body, very small amounts of some metal ions are essential, whereas others are highly poisonous.
Oct/Nov 2010
Explain why complexes of transition elements are frequently coloured.
Oct/Nov 2010
On the diagram below, draw a clear labelled sketch that shows the shape and symmetry of a typical d-orbital.
Oct/Nov 2011
On the diagram below, produce a neat labelled sketch that shows the shape and symmetry of a typical $d$-orbital.
Oct/Nov 2011
Write out the electronic configurations for these ions. $\text{Cr}^{3+}: 1s^2 2s^2 2p^6 \ldots$ $\text{Mn}^{2+}: 1s^2 2s^2 2p^6 \ldots$
Oct/Nov 2011
What does the term ligand mean when used in the chemistry of the transition elements?
Oct/Nov 2011
Write down what you would see, and write equations for the reactions that occur, when silicon(IV) chloride and phosphorus(V) chloride are mixed separately with water. silicon(IV) chloride phosphorus(V) chloride
Oct/Nov 2012
Complete the electronic configuration for the $\text{Cu}^{2+}$ ion below. $1s^2\ 2s^2\ 2p^6$ …
Oct/Nov 2012
Complete the electron configurations of Ni and $\text{Ni}^{2+}$.
Oct/Nov 2014
Complete the electron arrangements for Ni and $\text{Ni}^{2+}$.
Oct/Nov 2014
Transition elements show characteristic properties because their $d$ orbitals are only partly filled.
Oct/Nov 2014
Copper is classified as a transition element and has atomic number 29.
Oct/Nov 2016
Cobalt is a transition element that forms complex ions with oxidation states $+2$ and $+3$. Explain what the term transition element means.
Oct/Nov 2016
Transition elements are important metals because they have characteristic properties.
Oct/Nov 2016
Cobalt is a transition element that forms complex ions with oxidation states $+2$ and $+3$. Explain what is meant by the term transition element.
Oct/Nov 2016
Describe and explain the differences in density and melting point between cobalt and calcium.
Oct/Nov 2017
Complete these electronic structures: • iron atom, Fe: $1s^22s^22p^6\,\ldots$ • iron(III) ion, $\text{Fe}^{3+}$: $1s^22s^22p^6\,\ldots$
Oct/Nov 2017
Define the term transition metal complex
Oct/Nov 2017
Describe and explain how cobalt’s density and melting point compare with those of calcium.
Oct/Nov 2017
Fill in the missing parts of these electronic structures: • iron atom, Fe: $1s^2 2s^2 2p^6 \,\ldots$ • iron(III) ion, $\text{Fe}^{3+}$: $1s^2 2s^2 2p^6 \,\ldots$
Oct/Nov 2017
Transition elements and their compounds are commonly employed as catalysts. Which element is present in the catalyst used in the Contact process, and what oxidation number does it have?
Oct/Nov 2018
Ethanedioate ions, $\text{C}_2\text{O}_4^{2-}$, act as bidentate ligands. Explain what the term ligand means.
Oct/Nov 2018
Complete the table to show how many unpaired electrons are present in the $3d$ and $4s$ orbitals of each isolated gaseous atom: Cr, Mn and Fe.
Oct/Nov 2018
Complete the electronic configurations for Cu and $\text{Cu}^{2+}$.
Oct/Nov 2018
The reaction scheme illustrates a few reactions involving $[\text{Co}(\text{H}_2\text{O})_6]^{2+}$.
Oct/Nov 2018
Ethanedioate ions, $\text{C}_2\text{O}_4^{2-}$, serve as bidentate ligands.
Oct/Nov 2018
Complete the table by giving the total number of unpaired electrons in the $3d$ and $4s$ orbitals for each isolated gaseous atom: $\text{Cr}$, $\text{Mn}$ and $\text{Fe}$.
Oct/Nov 2018
Manganese, chromium and ruthenium all belong to the transition elements.
Oct/Nov 2019
Several copper compounds, for example $\text{CuSO}_4$ and $\text{Cu(NO}_3)_2$, contain $\text{Cu}^{2+}$ ions. In aqueous solution, this ion is present as the $[\text{Cu(H}_2\text{O)}_6]^{2+}$ complex ion, with water acting as a monodentate ligand.
Oct/Nov 2019
Manganese, chromium and ruthenium are each transition elements.
Oct/Nov 2019
A solution is prepared by dissolving $\text{CuSO}_4\cdot5\text{H}_2\text{O}$ in excess aqueous ammonia. The resulting solution contains the copper complex $[\text{Cu}(\text{NH}_3)_4]^{2+}$. The $[\text{Cu}(\text{NH}_3)_4]^{2+}$ solution is then warmed gently in a fume cupboard so that $\text{NH}_3$ is given off. Some $\text{NH}_3$ remains dissolved and some is present as $\text{NH}_3(g)$. The solution changes colour; a precipitate of $\text{Cu(OH)}_2$ forms and is collected. A sample of $\text{Cu(OH)}_2$ is added to concentrated hydrochloric acid. A reaction occurs and a coloured copper complex, Y, is produced. A sample of $\text{Cu(OH)}_2$ is added to dilute sulfuric acid. A reaction occurs and a coloured copper complex, Z, is produced. $[\text{Cu}(\text{NH}_3)_4]^{2+}$, Y and Z are not the same colour.
Oct/Nov 2020
If $1.0\,\text{mol dm}^{-3}\;\text{Na}_2\text{S}_2\text{O}_3(aq)$ is introduced into a solution that contains $\text{Ag}^+(aq)$ ions, the linear complex $P$ is produced. In $P$, the $\text{S}_2\text{O}_3^{2-}$ ions act as monodentate ligands.
Oct/Nov 2020