Source: https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-12-carbonates-halides-and-sulfates [Revision notes](https://senecalearning.com/en-gb/revision-notes.md) › [GCSE](https://senecalearning.com/en-gb/revision-notes/gcse.md) › [Science Practicals](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals.md) › [National Curriculum](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum.md) › Carbonates, Halides & Sulfates # Carbonates, Halides & Sulfates Science Practicals: GCSE, topic 2.1.12 ## Reactions of Carbonates When carbonates react with dilute acids, the following products are formed: ### A salt [GIF: A salt](https://media.giphy.com/media/3o7P4F86TAI9Kz7XYk/giphy.mp4) ### Carbon dioxide [GIF: Carbon dioxide](https://media.giphy.com/media/3osxY5iekJYTaYXo52/giphy.mp4) ### Water [GIF: Water](https://media.giphy.com/media/JXHhI4o9NCf8k/giphy.mp4) ## Testing for Halides Halide ions are negatively charged (they are anions). There are 2 steps to halide testing: ### Add dilute nitric acid ![Add dilute nitric acid](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/8.3.2%20Identifying%20ions%202/beakers-309864_640-min.jpg) - Add dilute nitric acid to an unknown solution. - This removes carbonate ions. These could disrupt test results by forming a precipitate with the silver ions added in step 2. ### Add silver nitrate ![Add silver nitrate](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/8.3.2%20Identifying%20ions%202/old-932218_640-min.jpg) - Add silver nitrate to the same solution. - If halide ions are present, they will form a precipitate with the silver ions: - Ag+(aq) + Cl-(aq) → AgCl(s) (silver chloride is white). - Ag+(aq) + Br-(aq) → AgBr(s) (silver bromide is cream). - Ag+(aq) + I-(aq) → AgI(s) (silver iodide is pale yellow). ## Testing for Sulfates Sulfates are compounds that contain SO42- ions. There are 2 steps to sulfate testing: ### Add dilute hydrochloric acid ![Add dilute hydrochloric acid](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/8.3.2%20Identifying%20ions%202/beakers-309864_640-min.jpg) - Add dilute hydrochloric acid to an unknown solution. - This removes carbonate ions. These could disrupt test results by forming a precipitate with the barium ions added in step 2. ### Add barium chloride ![Add barium chloride](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/8.3.2%20Identifying%20ions%202/precipitade-min.jpg) - Add barium chloride to the same solution. - If sulfates are present, the white precipitate barium sulfate will form: - Ba2+(aq) + SO42-(aq) → BaSO4(s) ## Test yourself on Carbonates, Halides & Sulfates - How could you confirm that carbonates produce carbon dioxide when they react with dilute acids? - Why is dilute nitric acid added to a solution before it is tested for halide ions? - What ions do carbonates contain? - What colour are the following halide precipitates? - Which of the following are involved in testing for halides? [Practise this topic for free](https://app.senecalearning.com/classroom/course/35d9e7b0-1dfb-11e8-b5b7-7546c70e1a36/section/17ac1929-968c-464d-9ed5-dbc71ba61012/session) - Previous topic: [2.1.11 Identifying Ions](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-11-identifying-ions.md) - Next topic: [2.1.13 Flame Emission Spectroscopy](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-13-flame-emission-spectroscopy.md) ## Science Practicals: GCSE contents ### 1 Biology - 1.1 Practicals - [1.1.1 Microscope & Bacteria](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-1-microscope-and-bacteria.md) - [1.1.2 Bacteria](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-2-bacteria.md) - [1.1.3 Osmosis Tests](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-3-osmosis-tests.md) - [1.1.4 Osmosis & Food Tests](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-4-osmosis-and-food-tests.md) - [1.1.5 Enzymes](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-5-enzymes.md) - [1.1.6 Enzymes 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-6-enzymes-2.md) - [1.1.7 Photosynthesis & Plant Responses](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-7-photosynthesis-and-plant-responses.md) - [1.1.8 Photosynthesis Experiments](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-8-photosynthesis-experiments.md) - [1.1.9 Reaction Time](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-9-reaction-time.md) - [1.1.10 Quadrats](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-10-quadrats.md) - [1.1.11 Decay](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-11-decay.md) ### 2 Chemistry - 2.1 Practicals - [2.1.1 Salts](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-1-salts.md) - [2.1.2 Neutralisation](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-2-neutralisation.md) - [2.1.3 Titration](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-3-titration.md) - [2.1.4 Electrolysis](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-4-electrolysis.md) - [2.1.5 Electrolysis 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-5-electrolysis-2.md) - [2.1.6 Rate of Reaction](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-6-rate-of-reaction.md) - [2.1.7 Rate of Reaction 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-7-rate-of-reaction-2.md) - [2.1.8 Chromatography](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-8-chromatography.md) - [2.1.9 Identifying Gases](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-9-identifying-gases.md) - [2.1.10 Identifying Gases 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-10-identifying-gases-2.md) - [2.1.11 Identifying Ions](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-11-identifying-ions.md) - [2.1.12 Carbonates, Halides & Sulfates](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-12-carbonates-halides-and-sulfates.md) - [2.1.13 Flame Emission Spectroscopy](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-13-flame-emission-spectroscopy.md) - [2.1.14 Water Purification](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-14-water-purification.md) - [2.1.15 Water Purification 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-15-water-purification-2.md) ### 3 Physics - 3.1 Practicals - [3.1.1 Specific Heat Capacity](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-1-specific-heat-capacity.md) - [3.1.2 Thermal Capacity & Insulation](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-2-thermal-capacity-and-insulation.md) - [3.1.3 Latent Heat](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-3-latent-heat.md) - [3.1.4 Resistance & Current](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-4-resistance-and-current.md) - [3.1.5 Resistance & Current 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-5-resistance-and-current-2.md) - [3.1.6 Density](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-6-density.md) - [3.1.7 Density 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-7-density-2.md) - [3.1.8 Force & Extension - Springs](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-8-force-and-extension-springs.md) - [3.1.9 Waves - Ripple Tank](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-9-waves-ripple-tank.md) - [3.1.10 Light](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-10-light.md) - [3.1.11 Light Reflection & Refraction](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-11-light-reflection-and-refraction.md) - [3.1.12 Radiation](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-12-radiation.md) - [3.1.13 Radiation 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-13-radiation-2.md)