Chemical Reactions and Stoichiometry Chemical reaction, a process in which one or more substances, the reactants, are converted to one or more different substances, the products. Substances are either chemical elements or compounds. A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products. Investigation Mass Changes in Chemical Reactions 1: Law Of Conversation of Mass The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction, but merely changed from one form to another. (ACSCH046) Experiment: Conservation of Mass p142 Chemistry in Investigation 7.1 For this investigation use the working scientifically scaffold: Problem does mass change during a chemical reaction? – Aim to observe mass before and after a reaction. – Hypothesis the mass will not change because are just rearranged in a chemical – reaction. Equipment beakers, silver nitrate and sodium chloride, electronic balance – Risk assessment skin and eye irritants; appropriate disposal of waste CH11/12-2a, 2b – Procedure 10mL each solution, weigh mass before and after, compare masses. – CH11/12-3a, 3b Results – record masses, photos before and after Discussion Conclusion mass before and after were the same, law of conservation of mass.. – Validity? Reliability? CH11/12-4a, 4b
Chemical Reactions and Stoichiometry Chemical reaction, a process in which one or more substances, the reactants, are converted to one or more different substances, the products. Substances are either chemical elements or compounds. A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products. Investigation Mass Changes in Chemical Reactions 1: Law Of Conversation of Mass The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction, but merely changed from one form to another. Experiment: Conservation of Mass p142 Chemistry in (ACSCH046) Investigation 7.1 For this investigation use the working scientifically scaffold: Problem – does mass change during a chemical reaction? Aim – to observe mass before and after a reaction. Hypothesis – the mass will not change because are just rearranged in a chemical reaction. Equipment – beakers, silver nitrate and sodium chloride, electronic balance Risk assessment – skin and eye irritants; appropriate disposal of waste CH11/12-2a, 2b Procedure – 10mL each solution, weigh mass before and after, compare masses. CH11/12-3a, 3b Results – record masses, photos before and after Discussion Conclusion – mass before and after were the same, law of conservation of mass.. Validity? Reliability? CH11/12-4a, 4b