Chemistry 0620 · IGCSE · Relative masses of atoms and molecules

Relative masses of atoms and molecules — practice question

This question deals with masses, volumes and moles.
(a)[1]

Which term is defined by the statement below? The average mass of naturally occurring atoms of an element on a scale where the $^{12}\text{C}$ atom has a mass of exactly 12 units.

(b)[2]

Explain why relative molecular mass is suitable for butane but not for potassium fluoride.

(c)[3]

Determine how many moles of element Y are present in 60.0 cm^{3}. Calculate the relative molecular mass of element Y and then suggest the identity of element Y.

(d)[4]

Calculate the empirical formula for this oxide of phosphorus.

(e)[2]

Calculate the mass for one mole of this oxide of phosphorus.

Worked solution & mark scheme

This 12-mark question has a full step-by-step worked solution and mark scheme. One marking point: Relative atomic mass.

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