This question is about lithium carbonate tablets, which are commonly prescribed as mood-stabilising medications.
Lithium carbonate contains lithium ions (Li+Li^+Li+) and carbonate ions (CO32−CO_3^{2-}CO32−).
A student wants to test a lithium carbonate tablet to confirm the presence of both lithium ions and carbonate ions. They are provided with:
Plan an investigation to show the presence of lithium ions and carbonate ions in the tablet. You should include the expected results of the tests for both ions.
Besides the active pharmaceutical ingredient, the tablet contains other substances such as binders, disintegrants, and coatings. These ingredients are present in exact, pre-determined quantities to ensure the tablet dissolves at the correct rate in the body. What chemical term is used to describe mixtures workload as a useful product in this way?
A single tablet has a total mass of 1.35 g and contains 400 mg of lithium carbonate. Calculate the percentage by mass of lithium carbonate in this tablet. Give your answer to 3 significant figures.
28 exam-style questions on AQA GCSE Chemistry 8.1 Purity, formulations and chromatography, covering 8.1.1 Pure substances, 8.1.2 Formulations, and 8.1.3 Chromatography. Each one has a worked solution and a mark scheme showing where the marks go.