Question

In a constant-pressure calorimeter, 60.0 mL of 0.330 M Ba(OH)2 was added to 60.0 mL of 0.660 M HCl. The reaction caused the temperature of the solution to rise from 23.72 °C to 28.22 °C. If the solution has the same density and specific heat as water (1.00 g/mL and 4.184 J/g·K, respectively), what is ΔH for this reaction (per mole of H2O produced)? Assume that the total volume is the sum of the individual volumes.

Answer 1

Ba(OH)2 + 2HCl -------> BaCl2 + 2H2O

no of moles of Ba(OH)2 = molarity * volume in L

                                      = 0.33*0.06 = 0.0198moles

no of moles of HCl   = molarity * volume in L

                              = 0.66*0.06 = 0.0396 moles

1 mole of Ba(OH)2 react with 2 moles of HCl

0.0198 moles of Ba(OH)2 react with = 2*0.0198 = 0.0396 moles

Two reactant ate present stoichiometric ratio. No exess and no limiting reactant.

2 moles of HCl react with ba(OH)2 gives 2 moles of H2O

0.0396 moles of HCl react withBa(OH)2 to gives 0.0396 moles of H2O

mass of solution = volume * density

                           = 120*1 = 120g

q   = mCt

    = 120*4.184*(28.22-23.72)   = 2259.36J

   2259.36/0.0396 = 57054J/mole = 57.054KJ/mole >>>>> answer