Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can describe the difference between a pure substance and a mixture in terms of the types of particle they contain. (Guide: “Pure substances and mixtures at the particle level”; Practice Q1)
- I can explain why a compound made of two elements is still a pure substance. (Guide: Figure 1; Practice Q1)
- I can explain why a pure compound has a fixed mass percent of each element but a mixture does not. (Guide: “Mass percent: fixed for a compound, variable for a mixture”)
- I can state what elemental analysis measures and the two things it can tell you: relative numbers of atoms and purity. (Guide: “Is the sample pure?”)
Calculation
- I can find the range of mass percents possible for a mixture of two named compounds. (Practice Q2, Q5a)
- I can calculate the purity of a sample when the impurity contains none of the analysed element. (Guide: Worked example 1; Practice Q3, Q4a, Q6c)
- I can find the amount of each component in a two-component mixture when both contain the analysed element. (Guide: Worked example 2; Practice Q5b)
- I can find the total mass of an element that comes from two different components. (Practice Q4b)
- I can convert analysis masses to moles to find the ratio of atoms in a sample. (Guide: Worked example 2 step 5; Guide: “Is the sample pure?”)
Reasoning
- I can tell the difference between the mass percent of an element in a sample and the mass percent of a compound in it. (Guide: “Common misconceptions”; Practice Q3)
- I can use repeated analysis data to decide whether a sample is pure, giving evidence from the numbers. (Practice Q6b)
- I can explain why a mole ratio that differs from the formula ratio shows a second substance is present, and which impurities could cause it. (Practice Q7)
All ticked? Move on to Topic 1.5, Atomic Structure and Electron Configuration, or return to the course roadmap.