Online Lab:  HEAT OF FORMATION OF MAGNESIUM OXIDE

REPORT SHEET

 

Name:                                                   Partner:                                                  

Section:                   Instructor:                                                    Date:                    

Reaction 1	Mg + HCl         MgCl2(aq) + H2(g)
Mass of solid Styrofoam Cup (Calorimeter)	__________ g
Mass of solid	__________ g
Moles of solid	_____________ mol
Mass of solution	___________ g
Initial temperature	_________ oC
Final temperature	_________ oC
∆T	_______________ oC
Heat gained by calorimeter, qcal	_______________ J
Heat gained by solution, qsoln	_______________ J
Total heat evolved in rxn, qrxn	_______________ J
qrxn per gram of solid	_______________ J/g
Molar heat of reaction, ∆H, kJ/mol	____________kJ/mol

Below, write the balanced equations and ∆H values for the three reactions (values for Reaction 2 and 3 from Page 2. Please write the current sign for each ∆H value):

Reaction 1.	__ kJ/mol
Reaction 2.	kJ/mol
Reaction 3.	kJ/mol

Using Hess’ Law, below show calculations for Heat of combustion for Mg:

Mg(s)+2HCl(aq) à MgCl2(aq) + H2(g)                         kJ/mol

MgCl2(aq)+H2O(l) à MgO(s)+2HCl(aq)                     kJ/mo

H2(g) +1/2O2(g) à H2O(l)                                        -kJ/mol

Mg(s)+1/2 O2(g) à MgO(s)                                       kJ/mol

Heat of Combustion for Mg, kJ/mol	_____ ____ kJ/mol
Experimental Heat of Formation of MgO, kJ/mol	_____ ____ kJ/mol
Theoretical Heat of Formation of MgO, kJ/mol	kJ/mol
Experimental Error, %	_________________________ %