The Hydrochloric Acid, Sodium Thiosulphate Reaction

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The Hydrochloric Acid, Sodium Thiosulphate Reaction Research: "Hydrochloric acid is a strong colourless acid formed when hydrogen chloride gas dissociates in water, used in industrial and laboratory processes. Hydrochloric acid is also produced in the stomach, where it initialises the digestion of proteins. Sodium thiosulphate is a white crystalline salt used as a fixer in photography and as a bleach." Encarta World English Dictionary When hydrochloric acid reacts with sodium thiosulphate, sulphur is created. Sulphur is a pale yellow colour; after the reaction the sulphur stays in the same container as the other products, meaning that the solution will be a pale yellow colour. Na2S2O3 + H++ Cl- [IMAGE] 2NaCl + S + SO2 + H2O Sodium thiosulphate solution Hydrochloric acid Sodium chloride solution Sulphur Sulphur dioxide Water "The sulphur does not start to form immediately, but begins to appear after a short time, turning the mixture cloudy. You cannot tell precisely when the reaction has stopped." AQA GCSE Higher Sulphur dioxide (SO2) is a colourless gas, belonging to the family of gases called sulphur oxides (SO_). It reacts on the surface of a variety of airborne solid molecules, is soluble in water and can be oxidised within airborne water droplets. Many factors can affect the rate of reaction; concentration, temperature, ratio of the substances, amount, stirring, and catalysts are these factors. Rate of reaction is the speed of reaction. In essays written by young scientists, they have used concentration as a variable in their experiments; some have used a light sensor, connected to a data logger, to measure the amount of light passing through the "cloudy" liquid. 1 moles = 6.02 ´1023 The particles in the hydrochloric acid and sodium thiosulphate need to collide to react, this is called the collision theory; a minimum force of collision is required for the reaction to take place; this is

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