Quantitative Chemistry & Chemical Change is one of 9 topics in the Grade 10 Physical Sciences CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. One mole of any substance contains how many particles?
6,022 x 10^23
1,000
100
3,14 x 10^8
Answer: 6,022 x 10^23 — One mole always contains 6,022 x 10^23 particles, a value known as Avogadro's constant.
Easy
2. The molar mass of a substance is defined as:
The mass, in grams, of exactly one mole of that substance
The mass of a single atom of that substance in grams
The number of moles in one gram of the substance
The volume occupied by one mole of the substance
Answer: The mass, in grams, of exactly one mole of that substance — Molar mass (M) is the mass in grams of one mole of a substance, with unit g/mol.
Medium
3. Using the approximate relative atomic masses H=1 and O=16, calculate the molar mass of water, H2O, in g/mol.
Answer: 18 — Molar mass of H2O = 2(1) + 16 = 18 g/mol.
