Two unlabelled samples are iron, Fe\mathrm{Fe}Fe, and iron(II) carbonate, FeCO3\mathrm{FeCO_3}FeCO3. A student adds dilute hydrochloric acid, HCl\mathrm{HCl}HCl, to each sample. Both samples fizz.
The gas made by sample Q turns limewater milky.
The formula of iron(II) chloride is FeCl2\mathrm{FeCl_2}FeCl2.
Explain which substance is sample Q.
Give the balanced symbol equation for the reaction of sample Q with hydrochloric acid.
112 exam-style questions on OCR GCSE Chemistry 3.3 Types of chemical reactions, covering 3.3.1 Oxidation and reduction in terms of oxygen, 3.3.2 Acids, alkalis and neutralisation, 3.3.3 The pH scale and measuring pH, 3.3.4 Oxidation and reduction in terms of electrons, 3.3.5 Dilute and concentrated, weak and strong acids, and 3.3.6 Hydrogen ion concentration and pH. Each one has a worked solution and a mark scheme showing where the marks go.