Class X Question 1: Chapter 1 – Chemical Reactions and Equations Science Why should a magnesium ribbon be cleaned before burning in air? Answer Magnesium is very reactive metal. When stored it reacts with oxygen to form a layer magnesium oxide on its surface. This layer of magnesium oxide is quite stable and prevents further reaction of magnesium with oxygen. The magnesium ribbon is cleaned by sand paper to remove this layer so that the underlying metal can be exposed into air. Question
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Chemical equations are the symbolic representations of chemical reactions that are made up of reactants and products. It is made up of the chemical formulas of the reactants and the chemical formula of the products. The reactants are the substances or chemicals that takes part in during a reaction and the products are the chemicals are the substances that result from the chemical reaction. Reactants are on the left side of the chemical equation and the products are on the right side of the chemical
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April 7th‚ 2015 Section- 109 Investigating Stoichiometry with Sodium Salts of Carbonic Acid Introduction- This experiment is intended to help find a better understanding of chemical stoichiometry through titrations of NaHCO3 and NA2CO3 with HCl. A chemical reaction is a process that involves rearrangement of the molecular or ionic structure of a substance‚ as opposed to a change in physical form in a nuclear reaction. Titration is when a measured amount of solution of unknown volume
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Summary This experiment will measure the rate of oxidation of iodide ions by persulphate ions to derive the rate law for the reaction. Starch will be added to the reaction to facilitate the measure of time during the reaction. The reactant solutions will contain (NH4)2SO4 and KI‚ represented as: (NH4)2S2O8 + 2KI -> I2 + (NH4)2SO4 + K2SO4 This can be simplified to: S2O82- + 2I- -> I2 + 2SO42- These equations can only be carried out and be visible after the iodine has completely
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three reactions that occurred in the test tubes where you combined potassium iodide‚ KI‚ and hydrogen peroxide‚ H2O2 (in part 1) of the experiment? (Give a detailed explanation of any observations that you made‚ i.e.‚ what made the colour change‚ what reactions happened?) ANSWER: 2. Use the information below to develop the necessary calculations for the rate of reaction from the solutions in part B of the experiment • Calculate the initial molarity
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Aim During this experiment I will be investigating if heating limestone and changing the concentration of the acid will affect the rate of reaction. Preliminary work Before doing our main experiment‚ we will have to conduct another experiment‚ to see what concentration of acid we will have to use. We done this using 0.1M‚ 0.5M and 1M of Hydrochloric acid‚ and 0.1g of powdered limestone‚ we used powdered limestone‚ as it would be a fairer test‚ I think this as all the particles of limestone will
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INTRODUCTION For this experiment we studied an oxidation-reduction reaction of magnesium and hydrochloric acid solution. We compared the experimental measured amount of a product and the amount predicted by the theoretical calculation of a balanced equation: Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2 (g) PROCEDURE First we obtained a strip of pre-cut magnesium ribbon‚ cleaned it with steel wool to remove any signs of oxidation from the strip (which would alter our results)‚ and then weighed it (individual
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Section: 9 - Malaya Topic: Types of Chemical Reaction A chemical reaction is a process that is usually characterized by a chemical change in which the starting materials (reactants) are different from the products. Chemical reactions tend to involve the motion of electrons‚ leading to the formation and breaking of chemical bonds. There are several different types of chemical reactions and more than one way of classifying them. Here are some common reaction types. However‚ if you are asked to name the
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energy and heat associated with chemical reactions and/or physical transformations. A reaction may release or absorb energy‚ and a phase may change‚ such as in melting and boiling. Thermochemistry focuses on these energy changes‚ particularly on the system ’s energy exchange with its surroundings. In combination with entropy determinations‚ it is used to predict whether a reaction is spontaneous or non-spontaneous‚ favourable or unfavourable. Chemical reactions can be divided into two based on the
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Exothermic and Endothermic Reactions The release of energy in chemical reactions occurs when the reactants have higher chemical energy than the products. The chemical energy in a substance is a type of potential energy stored within the substance. This stored chemical potential energy is the heat content or enthalpy of the substance. The collection of substances that is involved in a chemical reaction is referred to as a system and anything else around it is called the surroundings. If the enthalpy
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