Contents
Page Number
Areas
Title
2
Contents
3
.0.1, 1.0.2, 1.0.3
4
.1.1
5
.1.2, 1.1.3
6
.1.4,1.2.1
7
.2.2
8
Bibliography
.0.0- Introduction
.0.1- Focus Question- If the mass of magnesium reacted with hydrochloric acid is changed will the temperature of the solution increase and the total mass decrease.
.0.2- Hypothesis- If the mass of magnesium that is reacted with hydrochloric acid is changed the temperature of the solution will increase and the total mass will decrease.
.0.3- Theory- The reaction between magnesium and hydrochloric reaction is written as follows, Mg(s)+ 2HCL (aq)------ (MgCl2(aq)+H2 (g) (Ng, 2008, pg 1). This reaction goes through two distinct changes that both have an effect on the energy change in the reaction. Enthalpy refers to changes in energy in a compound (Assut, 2008, pg 1). Two distinct changes can occur. An endothermic change occurs when the energy being absorbed is grater then the energy being released whereas and exothermic change is when the energy being released is greater than the energy being absorbed. Energy is absorbed when bonds are broken and energy is released when they are formed (Newton, 2008, pg1). Energy change cannot be directly measured. However energy change affects the physical force of heat. Therefore a heat change is indicative of an energy change. If the heat increase in the solution the change will be exothermic and if the heat decreases the reaction will be endothermic. In respects to the formula Magnesium forms an ionic bond with chlorine to form the salt magnesium chloride. When this bond is formed energy is released in the form of an endothermic change, this energy drop would be quite small however because the bond is ionic and does not take much energy to create since magnesium and chorine bond easily. However the second change is that hydrogen breaks off from chlorine in the hydrochloric acid and hydrogen is released as a gas. The breaking of bonds would absorb energy therefore forming an exothermic reaction. Hydrogen and chorine however form a very strong covalent bond. Covalent bonds form between atoms with similar electronegative forces and are there for take a lot of energy to break ( Anissimov, 2008, pg 1) Since the endothermic change is weak and the exothermic change is strong it can be predicted that the overall change will be exothermic and therefore the solution will heat up. Temperature change in a chemical reaction can be measured with a device known as a calorimeter. A calorimeter measures the heat of the solution before the reaction has occurred and then again after the reactant has been added (Whel, 2008, pg 1). These two values can be mathematically manipulated to find the relative change in temperature. If two of the same substance have different masses it means there is more of the one substance. In a mass of a substance there is a certain amount of material that can be reacted. By increasing mass the amount of substance that may be reacted increases. Therefore if mass increased the amount that of substance reacted will increase as well providing there is enough of the reactant. This will in turn increase the energy change. Also if more of the substance reacts with the reactant more of the reactant will be used up. This means that if the magnesium is increased there will be more reaction with hydrochloric acid; this means that more hydrogen will be released as gas and the total mass of the solution will decrease. Henceforth the change in heat should be greater if their entire solution is lighter as more of the hydrochloric acid has been reacted and hydrogen lost as a gas.
Page Number
Areas
Title
2
Contents
3
.0.1, 1.0.2, 1.0.3
4
.1.1
5
.1.2, 1.1.3
6
.1.4,1.2.1
7
.2.2
8
Bibliography
.0.0- Introduction
.0.1- Focus Question- If the mass of magnesium reacted with hydrochloric acid is changed will the temperature of the solution increase and the total mass decrease.
.0.2- Hypothesis- If the mass of magnesium that is reacted with hydrochloric acid is changed the temperature of the solution will increase and the total mass will decrease.
.0.3- Theory- The reaction between magnesium and hydrochloric reaction is written as follows, Mg(s)+ 2HCL (aq)------ (MgCl2(aq)+H2 (g) (Ng, 2008, pg 1). This reaction goes through two distinct changes that both have an effect on the energy change in the reaction. Enthalpy refers to changes in energy in a compound (Assut, 2008, pg 1). Two distinct changes can occur. An endothermic change occurs when the energy being absorbed is grater then the energy being released whereas and exothermic change is when the energy being released is greater than the energy being absorbed. Energy is absorbed when bonds are broken and energy is released when they are formed (Newton, 2008, pg1). Energy change cannot be directly measured. However energy change affects the physical force of heat. Therefore a heat change is indicative of an energy change. If the heat increase in the solution the change will be exothermic and if the heat decreases the reaction will be endothermic. In respects to the formula Magnesium forms an ionic bond with chlorine to form the salt magnesium chloride. When this bond is formed energy is released in the form of an endothermic change, this energy drop would be quite small however because the bond is ionic and does not take much energy to create since magnesium and chorine bond easily. However the second change is that hydrogen breaks off from chlorine in the hydrochloric acid and hydrogen is released as a gas. The breaking of bonds would absorb energy therefore forming an exothermic reaction. Hydrogen and chorine however form a very strong covalent bond. Covalent bonds form between atoms with similar electronegative forces and are there for take a lot of energy to break ( Anissimov, 2008, pg 1) Since the endothermic change is weak and the exothermic change is strong it can be predicted that the overall change will be exothermic and therefore the solution will heat up. Temperature change in a chemical reaction can be measured with a device known as a calorimeter. A calorimeter measures the heat of the solution before the reaction has occurred and then again after the reactant has been added (Whel, 2008, pg 1). These two values can be mathematically manipulated to find the relative change in temperature. If two of the same substance have different masses it means there is more of the one substance. In a mass of a substance there is a certain amount of material that can be reacted. By increasing mass the amount of substance that may be reacted increases. Therefore if mass increased the amount that of substance reacted will increase as well providing there is enough of the reactant. This will in turn increase the energy change. Also if more of the substance reacts with the reactant more of the reactant will be used up. This means that if the magnesium is increased there will be more reaction with hydrochloric acid; this means that more hydrogen will be released as gas and the total mass of the solution will decrease. Henceforth the change in heat should be greater if their entire solution is lighter as more of the hydrochloric acid has been reacted and hydrogen lost as a gas.
