Throughout this lab the goal was to figure out the enthalpy of combustion of magnesium. Enthalpy (H) is the energy stored in a substance during its formation. The amount of energy that may be absorbed or released when a chemical reaction takes place is known as the change in enthalpy (ΔH). If a reaction absorbs heat, then it will be positive number and will be called an endothermic reaction. If a reaction releases heat, then it will have a negative number and will be called an exothermic reaction. Knowing the enthalpies of reactions can be useful since it allows humans to make products such as hand warmers which require an exothermic reaction.
The standard enthalpy of formation (ΔH°f) can be defined as the heat absorbed or released when one …show more content…
Any process that generates heat or exchanges it with its environment can be used in a calorimeter. Calorimetry has a very broad range of uses such as, drug design in pharmaceutical industry, or even the study of metabolic rates in biological systems. Hess’ law allows the experimenter to add up all the enthalpies of multiple reactions or stages to get the total enthalpy of change for the target equation. The enthalpies of several elementary steps can be calculated and then these can be added up in a process known as heat summation. Hess’ law states that energy changes are state functions. A state function is a value that does not depend on path taken to get to a specific value. The amount of energy only depends on the states of both the reactants and products, but not from the intermediate steps. This means that the enthalpy changes in chemical reactions are the same, whether the reaction occurs in one step or …show more content…
This can be found by reacting magnesium oxide and magnesium with hydrochloric acid to find their enthalpies. These reactions will occur inside a calorimeter which will provide all the necessary data to use the equation mentioned before to find the enthalpies for the two reactions. Then Hess’ law can be used with these two enthalpies and the enthalpy of formation for water to find the enthalpy of combustion for the target equation, Mg(s) + ½ O2(g) → MgO(s). The two reactions performed in this lab will be exothermic reactions which means that the molar enthalpy of combustion of magnesium will also be exothermic with a very low number because a lot of heat and light is
The standard enthalpy of formation (ΔH°f) can be defined as the heat absorbed or released when one …show more content…
Any process that generates heat or exchanges it with its environment can be used in a calorimeter. Calorimetry has a very broad range of uses such as, drug design in pharmaceutical industry, or even the study of metabolic rates in biological systems. Hess’ law allows the experimenter to add up all the enthalpies of multiple reactions or stages to get the total enthalpy of change for the target equation. The enthalpies of several elementary steps can be calculated and then these can be added up in a process known as heat summation. Hess’ law states that energy changes are state functions. A state function is a value that does not depend on path taken to get to a specific value. The amount of energy only depends on the states of both the reactants and products, but not from the intermediate steps. This means that the enthalpy changes in chemical reactions are the same, whether the reaction occurs in one step or …show more content…
This can be found by reacting magnesium oxide and magnesium with hydrochloric acid to find their enthalpies. These reactions will occur inside a calorimeter which will provide all the necessary data to use the equation mentioned before to find the enthalpies for the two reactions. Then Hess’ law can be used with these two enthalpies and the enthalpy of formation for water to find the enthalpy of combustion for the target equation, Mg(s) + ½ O2(g) → MgO(s). The two reactions performed in this lab will be exothermic reactions which means that the molar enthalpy of combustion of magnesium will also be exothermic with a very low number because a lot of heat and light is