DP Chemistry Questionbank

Suggest why experiments involving tetracarbonylnickel are very hazardous.

What is the charge on the iron(III) complex ion in [Fe(OH)₂(H₂O)₄]Br?

A.     0

B.     1+

C.     2+

D.     3+

Describe, in terms of the electrons involved, how the bond between a ligand and a central metal ion is formed.

Formulate an equation for the oxidation of nickel(II) sulfide to nickel(II) oxide.

The nickel obtained from another ore, nickeliferous limonite, is contaminated with iron. Both nickel and iron react with carbon monoxide gas to form gaseous complexes, tetracarbonylnickel, $\text{Ni(CO}{\text{)}}_{\text{4}}\text{(g)}$, and pentacarbonyliron, $\text{Fe(CO}{\text{)}}_{\text{5}}\text{(g)}$. Suggest why the nickel can be separated from the iron successfully using carbon monoxide.

Explain why iron forms many different coloured complex ions.

Ammonia is a stronger ligand than water. Which is correct when concentrated aqueous ammonia solution is added to dilute aqueous copper(II) sulfate solution?

A.     The d-orbitals in the copper ion split.

B.     There is a smaller splitting of the d-orbitals.

C.     Ammonia replaces water as a ligand.

D.     The colour of the solution fades.

Which of these statements are correct?

I. Zinc is not a transition element.
II. Ligands are Lewis bases.
III. Manganese(II) chloride is paramagnetic.

A.  I and II only

B.  I and III only

C.  II and III only

D.  I, II and III

What is the overall charge, $x$, of the chromium (III) complex?

$\left[\mathrm{Cr}\right({\mathrm{H}}_2\mathrm{O}{)}_4{\mathrm{Cl}}_2{]}^x$

A.  0

B.  1+

C.  2−

D.  3+

Describe the bond formation when urea acts as a ligand in a transition metal complex ion.

Explain why transition metals exhibit variable oxidation states in contrast to alkali metals.

Which complex ion contains a central ion with an oxidation state of +3?

A.  [PtCl₆]²⁻

B.  [Cu(H₂O)₄(OH)₂]

C.  [Ni(NH₃)₄(H₂O)₂]²⁺

D.  [Co(NH₃)₄Cl₂]⁺

State and explain the magnetic property of iron(II) and iron(III) ions.

Which is correct for the complex ion in [Fe(H₂O)₅Cl]SO₄?

Mg(OH)⁺ is a complex ion, but Mg is not regarded as a transition metal. Contrast Mg with manganese, Mn, in terms of one characteristic chemical property of transition metals, other than complex ion formation.

Predict two other chemical properties you would expect rhenium to have, given its position in the periodic table.

Which electrons are removed from iron (Z = 26) to form iron(II)?

A. two 3d electrons

B. two 4s electrons

C. one 4s electron and one 3d electron

D. two 4p electrons

What is the oxidation state of the metal ion and charge of the complex ion in [Co(NH₃)₄Cl₂]Cl?