424 THE TRANSITION ELEMENTS
(b) What is the highest oxidation state that you expect vanadium
to show in its compounds?
(c) Which of the following vanadium species do you expect to be
(i) the strongest reducing agent, (ii) the strongest oxidising
agent?
(d) State two physical properties of the element vanadium.
(1MB, A)
- Locate the element titanium (Ti) in the Periodic Table. Read
the following paragraph about its chemistry and answer the ques-
tions which follow.
When titanium dissolves in dilute hydrochloric acid, a violet solu-
tion containing titanium(III) ions is formed. This solution rapidly
decolorises acidified aqueous potassium permanganate at room
temperature. Titanium(IV) chloride is a colourless covalent liquid
completely hydrolysed by water. Titanium(III) chloride forms
hydrated titanium(III) ions in water and disproportionates when
heated in a vacuum.
(a) Construct ionic equations for (i) the dissolution of titanium
in hydrochloric acid and (ii) the reaction of titanium(III) ions
with permanganate ions in acid solution.
(b) Give the formula of the titanium compound formed when
titanium(IV) chloride reacts with water.
(c) State briefly what is meant by disproportionation.
(d) Give two physical properties of the element titanium.
(JMB, A)
- (a) Show by means of equations and experimental conditions*.
how the following may be prepared :
(i) A covalent halide of a Group IV (C-Pb) element:
Reagents : Conditions : Equations :
(ii) Anhydrous iron(II) chloride:
Reagents : Conditions : Equations :
(b) State two chemical differences between anhydrous iron(II)
chloride and silicon(IV) chloride.
(c) Explain why
(i) a solution of copper(II) chloride in concentrated hydro-
chloric acid is yellow,
(ii) the yellow solution turns blue on dilution,
(iii) the blue solution gives a precipitate with potassium iodide
solution. (JMB, A)
