Aysce
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Upon reading, I came across this and don't understand how mass is conserved in case 2 and 5, whilst in case 1,3,4,6, mass is not conserved. (The cases refer to the common ways of deciding that a chemical reaction has occurred)
Case 1: If a gas is evolved, for e.g. zinc granules dropped into hydrochloric acid solution.
Case 2: If a precipitate is formed when two solutions are mixed. e.g. Silver nitrate and sodium chloride solutions are mixed, silver chloride forms.
Case 3: If there is a change in colour e.g. When purple potassium permanganate solution is added to hydrogen peroxide, the mixture becomes colourless.
Case 4: If there is a significant change in temperature for the mixture e.g. When magnesium is burnt, the metal becomes very hot.
Case 5: If there is a disappearance of solid which is not merely physical dissolution of the solid in the solvent.
Case 6: If an odour is produced.
Sorry for the wall of text and help is greatly appreciated
Case 1: If a gas is evolved, for e.g. zinc granules dropped into hydrochloric acid solution.
Case 2: If a precipitate is formed when two solutions are mixed. e.g. Silver nitrate and sodium chloride solutions are mixed, silver chloride forms.
Case 3: If there is a change in colour e.g. When purple potassium permanganate solution is added to hydrogen peroxide, the mixture becomes colourless.
Case 4: If there is a significant change in temperature for the mixture e.g. When magnesium is burnt, the metal becomes very hot.
Case 5: If there is a disappearance of solid which is not merely physical dissolution of the solid in the solvent.
Case 6: If an odour is produced.
Sorry for the wall of text and help is greatly appreciated