DP Chemistry (first assessment 2025)
Question 22M.1A.SL.TZ2.10
| Date | May 2022 | Marks available | [Maximum mark: 1] | Reference code | 22M.1A.SL.TZ2.10 |
| Level | SL | Paper | 1A | Time zone | TZ2 |
| Command term | Identify | Question number | 10 | Adapted from | N/A |
10.
[Maximum mark: 1]
22M.1A.SL.TZ2.10
What is the type of bonding in a compound that has high boiling and melting points, poor electrical conductivity, and low solubility in water?
A. Ionic
B. Molecular covalent
C. Metallic
D. Giant covalent
[1]
Markscheme
D
Examiners report
58% of the candidates identified giant covalent bonding as the bonding in compounds with high melting and boiling points, poor electrical conductivity and low solubility in water. The most commonly selected distractor was ionic bonding. The question discriminated well between high-scoring and low-scoring candidates.
Syllabus sections
Structure 2. Models of bonding and structure » Structure 2.2—The covalent model » Structure 2.2.1—A covalent bond is formed by the electrostatic attraction between a shared pair of electrons and the positively charged nuclei. The octet rule refers to the tendency of atoms to gain a valence shell with a total of 8 electrons. Deduce the Lewis formula of molecules and ions for up to four electron pairs on each atom.
Structure 2. Models of bonding and structure » Structure 2.1—The ionic model » Structure 2.1.2—The ionic bond is formed by electrostatic attractions between oppositely charged ions. Deduce the formula and name of an ionic compound from its component ions, including polyatomic ions. Binary ionic compounds are named with the cation first, followed by the anion. The anion adopts the suffix “ide”. Interconvert names and formulas of binary ionic compounds.