Ionic Bonding：練習題

Which of the following statements correctly describes the bonding in a giant ionic lattice, such as that found in sodium chloride, \(NaCl\)?

Element \(X\) belongs to Group 2 of the Periodic Table, while element \(Y\) belongs to Group 17. What is the formula and the type of bonding in the compound formed between \(X\) and \(Y\)?

The diagram below displays the melting points of three ionic compounds. Which statement correctly explains why the melting point of magnesium oxide, \(MgO\), is significantly higher than that of sodium chloride, \(NaCl\)?

The properties of four substances are shown below. Which substance is most likely an ionic compound?

Substance A: Melting point \(44^{\circ}C\); Electrical conductivity (solid): No; Electrical conductivity (molten): No
Substance B: Melting point \(1085^{\circ}C\); Electrical conductivity (solid): Yes; Electrical conductivity (molten): Yes
Substance C: Melting point \(772^{\circ}C\); Electrical conductivity (solid): No; Electrical conductivity (molten): Yes
Substance D: Melting point \(1610^{\circ}C\); Electrical conductivity (solid): No; Electrical conductivity (molten): No

Which statement best explains why solid potassium iodide, \(KI\), is an electrical insulator, but aqueous potassium iodide is an electrical conductor?

Explain, in terms of its lattice structure, why potassium oxide has a high melting point.

A compound consists of aluminum and oxygen.
(a) Deduce the chemical formula of this compound based on the charges of its ions.
(b) Account for why this compound can conduct electricity in the molten state but not in the solid state.

A student proposes that calcium chloride, \(CaCl_{2}\), and sodium chloride, \(NaCl\), have different melting points. Compare the strength of the electrostatic forces in both lattices by considering the charges of the ions involved.

(a) Lithium (proton number 3) reacts with sulfur (proton number 16) to form an ionic compound.
(i) Describe the formation of ions when lithium reacts with sulfur in terms of electron transfer.
(ii) Predict the chemical formula of the compound formed.
(b) Explain, in terms of structure and bonding, why this compound has a high melting point.

The diagram in a textbook shows the electrolysis of molten lead(II) bromide, \(PbBr_{2}\).
(a) Explain why lead(II) bromide must be molten for electrolysis to occur, referring to the 'giant lattice' and the 'mobility of ions'.
(b) Predict the products formed at the positive electrode (anode) and the negative electrode (cathode).
(c) Construct the ionic half-equations for the reactions occurring at both electrodes.
(d) Describe the visual changes you would expect to see at each electrode during this process.