of something is 6.02 × 10²³ of it. The mass of a mole of a substance is its relative mass expressed in grams.

is a piece of equipment that is designed for a particular use.

is the ability to change between units of measurement.

refers to how close a measured value is to the true or standard value.

is the range of measurements within which the true value can be expected to be found. On apparatus, it is half the value of one resolution marking.

Representations of a mole

Combined science

In the Making salts unit, pupils will learn about the production of pure salts, concentration and strength of acids, and what makes acids acidic and how bases can neutralise them.

In the Understanding Chemical Reactions unit, pupils learned about how atoms rearrange during chemical reactions and the conservation of mass.

Calculations involving masses

Physical activity and equipment requiring safe use

What does one mole of any substance contain?

Calculate the substance's relative formula mass.

Divide the mass of the substance by its relative formula mass.

Order the following steps in the process of converting grams to moles.

Why is it important to choose the appropriate apparatus for measurements in chemistry?

how close a measured value is to the true value

the number of significant figures in a measurement

Which of the following best describes the term "accuracy"?

If the relative formula mass of sodium chloride (NaCl) is 58.5, what is the mass of 2 moles of NaCl? Give the answer to 3 significant figures.

Calculate the number of SO₄²⁻ ions in 34 g of Al₂(SO₄)₃. The answer is {{}} × 10²³. Give your answer to 3 significant figures.

Which of the following is a substance made of two or more elements chemically combined?

If an oxygen molecule consists of two oxygen atoms, what is its relative formula mass (Mr)?

a unit measuring the purity of a substance

a unit representing a certain number of particles

a unit representing the density of a substance

Which of the following best describes a mole?

To convert 50 grams of water to moles of water (Mr of 18), you would ...

the percentage of a sample that is water.

the relative amounts of each element in a compound.

the ratio of solute to solvent in a mixture.

What does the term "percent composition" refer to in chemistry?

Calculate the moles of methane (CH₄) in a sample of 55.2 grams. Give your answer to 2 significant figures.

Content guidance

Risk assessment required - equipment

Adult supervision required

Starter Quiz