9701 MCQ Solution 7

Question 7: [Physical > Bonding]:

Which of the following exists in the solid state as a giant covalent lattice?

A ice

B iodine

C silicon(IV) oxide

D tin(IV) chloride

Reference: Past Exam Paper – November 2002 Paper 1 Q7

Solution 7:

Answer: C.

Ice exists as a crystal lattice. Although the molecules it is composed of (H₂O) are covalently bonded this bonding does not follow throughout the structure. In the structure the molecules are held together with strong intermolecular forces called hydrogen bonds. Thus eliminating option A as the correct answer. Iodine exists as a simple covalent compound. The individual iodine atoms have a strong covalent bond. However the molecules of iodine (I₂) are held together by weak Van der Waals forces. This eliminates option B as the correct answer. Silicon(IV) oxide is 1 of the 3 giant molecular compounds we study about. Each silicon atom is covalently bonded to 4 oxygen atoms and each oxygen atom is covalently bonded to 2 silicon atoms. This structure continues throughout the solid hence C is the correct option. Tin(IV) chloride is a transition element compound and thus most likely an ionic compound thus eliminating option D as the correct answer.