Question detail

Calculate the relative formula mass of sodium chloride (NaCl) (A-level cue ba071b5d focus)

Try the question, check the answer, then read the explanation to understand the curriculum point.

Show answer Topic hub Objective page

At a glance

MCQ

Type

practice

Style

Topic

Amount of substance

Question

A. 58.5 g/mol
B. 60 g/mol (A-level cue ba071b5d distractor 1)
C. 56 g/mol (A-level cue ba071b5d distractor 2)
D. 54 g/mol (A-level cue ba071b5d distractor 3)

Answer

58.5 g/mol

Explanation

The correct option is 58.5 g/mol. 58.5 g/mol is correct because it supports the objective: Calculate relative molecular or formula mass from a chemical formula and relative atomic masses.. The reasoning stays within Relative atomic mass and relative molecular mass and avoids drifting into a similar A-Level Chemistry idea. This version is uniquely anchored to Relative atomic mass and relative molecular mass. Retrieval anchor: A-level cue ba071b5d. This item is treated as conceptual revision rather than a formal calculation item because the validated answer is an explanation or option choice, not a worked numerical response.

Common mistake

Misunderstanding Relative Molecular Mass Calculation

Students often confuse the relative molecular mass (Mr) with the sum of atomic masses without considering the correct number of each atom in the formula.

To calculate the relative molecular mass, use the formula: Mr = sum(Ar of all atoms in the formula). For example, for H2O, substitute: Mr = (2 x Ar of H) + (1 x Ar of O) = (2 x 1) + (1 x 16) = 2 + 16 = 18 g/mol.

Related flashcards

Flashcard 1 of 5

Press Space to flip, arrows to move