Lab: What Is The Molar Enthalpy Of Formation Of Magnesium Oxide?
Hess Law Lab DESIGN
Aspect 1: Problem: What is the molar enthalpy of formation of magnesium oxide? Variables: Manipulated: None Responding: None Controlled: Isolation of calorimeter, concentrations of substances involved.
Aspect 2: Background Information: Assumptions: Specific heat capacity of water, we assume that the acid has the same qualities as water including heat capacity, and we assume the enthalpy of formation for magnesium oxide from the data booklet for theoretical value. Hess’s Law: Hess' law states that the energy change for any chemical or physical process is independent of the pathway or number of steps required to complete the process provided that the final and initial reaction conditions are …show more content…
Mg(s)+ O2(g) MgO(s)
2. MgO(s)+2HCl(aq) MgCl2(aq)+H2O(l)
3. Mg(s)+2HCl(aq) MgCl2(aq)+H2(g)
4. H2(g)+ O2(g) H2O(l) + 285.8kJ
Part 1: Determining ΔH of Reaction (2)
1. Set up the simple calorimeter refer to figure 9.16 above. Using a graduated cylinder, add 100 mL of 1.00mol/L HCl(aq) to the calorimeter.
2. Record the initial temperature of the HCl(aq) to the nearest tenth of a degree.
3. Find the mass of no more than 0.80 grams of MgO(s) powder. Record exact mass.
4. Add the MgO(s) powder to the calorimeter containing the HCl(aq) swirl the solution gently, recording the highest temperature reached.
5. Dispose as directed by teacher.
Part 2: Determining ΔH of reaction (3)
1. Using a graduated cylinder, add 100mL of 1.00mol/L HCl to the calorimeter.
2. Record initial temp. of hydrochloric acid to the nearest tenth of a degree.
3. If you are using magnesium ribbon, sand ribbon to desired mass. Determine mass no more than 0.50 grams of magnesium. Record the exact mass.
4. Add the Mg(s) to the calorimeter containing the HCl(aq). Swirl the solution gently, recording the highest temperature, tf , reached.
5. Dispose as
Aspect 1: Problem: What is the molar enthalpy of formation of magnesium oxide? Variables: Manipulated: None Responding: None Controlled: Isolation of calorimeter, concentrations of substances involved.
Aspect 2: Background Information: Assumptions: Specific heat capacity of water, we assume that the acid has the same qualities as water including heat capacity, and we assume the enthalpy of formation for magnesium oxide from the data booklet for theoretical value. Hess’s Law: Hess' law states that the energy change for any chemical or physical process is independent of the pathway or number of steps required to complete the process provided that the final and initial reaction conditions are …show more content…
Mg(s)+ O2(g) MgO(s)
2. MgO(s)+2HCl(aq) MgCl2(aq)+H2O(l)
3. Mg(s)+2HCl(aq) MgCl2(aq)+H2(g)
4. H2(g)+ O2(g) H2O(l) + 285.8kJ
Part 1: Determining ΔH of Reaction (2)
1. Set up the simple calorimeter refer to figure 9.16 above. Using a graduated cylinder, add 100 mL of 1.00mol/L HCl(aq) to the calorimeter.
2. Record the initial temperature of the HCl(aq) to the nearest tenth of a degree.
3. Find the mass of no more than 0.80 grams of MgO(s) powder. Record exact mass.
4. Add the MgO(s) powder to the calorimeter containing the HCl(aq) swirl the solution gently, recording the highest temperature reached.
5. Dispose as directed by teacher.
Part 2: Determining ΔH of reaction (3)
1. Using a graduated cylinder, add 100mL of 1.00mol/L HCl to the calorimeter.
2. Record initial temp. of hydrochloric acid to the nearest tenth of a degree.
3. If you are using magnesium ribbon, sand ribbon to desired mass. Determine mass no more than 0.50 grams of magnesium. Record the exact mass.
4. Add the Mg(s) to the calorimeter containing the HCl(aq). Swirl the solution gently, recording the highest temperature, tf , reached.
5. Dispose as