In a constant-pressure calorimeter, 60.0 mL of 0.300 M Ba(OH)2 was added to 60.0 mL of 0.600 M HCl. The reaction caused the temperature of the solution to rise from 21.75 °C to 25.84 °C. If the solution has the same density and specific heat as water (1.00 g/mL and 4.184 J/g·°C, respectively), what is ΔH for this reaction (per mole of H2O produced)? Assume that the total volume is the sum of the individual volumes.

1 answer

..Ba(OH)2 + 2HCl ==> BaCl2 + 2HCl

mols Ba(OH)2 = 0.060 x 0.300 = 0.18
mols HCl = 0.060 x 0.600 = 0.036

mols Ba(OH)2 left = 0
mols HCl left = 0
mols H2O formed = 0.036

q = dH = mass H2O x specific heat H2O x (Tfinal-Tinitial)
Then convert J to kJ. That is ? kJ for 0.036. To find per mol it is
dH/0.036 = ? kJ/mol. Approx 57 kJ/mol.