posted by Ag10 on .
In a constant-pressure calorimeter, 50.0 mL of 0.320 M Ba(OH)2 was added to 50.0 mL of 0.640 M HCl. The reaction caused the temperature of the solution to rise from 23.47 °C to 27.83 °C. If the solution has the same density and specific heat as water, what is ΔH for this reaction (per mole of H2O produced)? Assume that the total volume is the sum of the individual volumes.
mols Ba(OH)2 = M x L = ? about 0.016
mols HCl = M x L = about 0.032
The reaction is stoihciometric.
Ba(OH)2 + 2HCl ==> BaCl2 + 2H2O
qrxn = mass H2O x specific heat H2O x (Tfinal-Tinitial) = about 1800 J
qrxn = delta H for 0.032 mols H2O formed
therefore, delta H/mol = about 1800 J/0.032 = ? joule/mol. Generally these are quoted as kJ/mol.