Determination Of The Valency Of Magnesium Essays

Determination Of The Valency Of Magnesium Essays Determination Of The Valency Of Magnesium Paper Determination Of The Valency Of Magnesium Paper 1. To determine the stoichiometry of the magnesium 2. To study the quantitative relations between amounts of reactants and products of the reaction. Theory Background : Stoichiometry is the study of the combination of elements in chemical reactions. Stoichiometry refers to the relative number of atoms of various elements found in a chemical substance and is often useful in characterizing a chemical reaction. The related term stoichiometric is often used in thermodynamics to refer to the perfect mixture of a fuel and air. Stoichiometry is often used to balance chemical equations. In this experimet, a known starting mass of magnesium and the measured collection of hydrogen gas will be used to determine the reaction stoichiometry. Stoichiometry rests upon the law of conservation of mass, the law of definite proportions and the law of multiple proportions. In general, chemical reactions combine in definite ratios of chemicals. Since chemical reactions can neither create nor destroy matter, nor transmute one element into another, the amount of each element must be the same throughout the overall reaction. This experiment determines the stoichiometry of a reaction of magnesium and hydrochloric acid(HCl). The relationship between moles of magnesium reacted and moles of hydrogen produced are plotted. Magnesium ribbon is a strip of magnesium that is solid at room temperature. When mixed with hydrochloric acid it produces magnesium chloride, which is a liquid and hydrogen gas. The below is the equation that occurs: Mg + 2HCl MgCl2 + H2 The word stoichiometry is also used for stoichiometry compound (eg: MgCl the proportion molecule ratio is 1:2). Valency is the adj of valence, which means the valence electron of the atom that is usable for reaction. Valency can also be defined as a measure of the number of chemical bonds formed by the atoms of a given element. In this experiment, the starting weight of magnesium is already known, so hydrogen gas collected can be measured to calculate the stoichiometry reaction, including the valency and the proportional molecule. The purpose of this experiment is to find out the quantitative relations between amounts of reactants and products between magnesium and HCl which is X, by calculating the presence hydrogen atom after the reaction is completed. The value of X is denoted in the following equation, Mg + X HCl i MgClx + X/2 H2 We know that magnesium will react with hydrochloric acid to produce hydrogen gas and magnesium chloride (MgCI) salt. MgCI is soluble but not hydrogen gas, so the gas can be collected in the burette using a filtering funnel. In this experiment, a limiting factor is needed to control the reaction. Magnesium is the best choice since it is in solid form and can be easily fixed in a space compared to hydrochloric acid in aqueous form, so excess hydrochloric acid will ensure that all the known amount of magnesium have reacted. When the volume of the hydrogen gas is obtained, the mole of the gas can be calculated, then substituted into the formula and to get the amount of mole of each molecule, and the difference between how many magnesium we had put in and how many actually reacted can be compared.