Question

A 150.0 mL sample of 0.300 mol/L sulfuric acid is mixed with 100.0 mL of
potassium hydroxide. The initial temperature of both solutions is 21.5 C. After
the reaction, the final temperature of the mixture is 30.0 C. Calculate the molar
enthalpy of neutralization of sulfuric acid.

Answer 1

c(H₂O)=4200 J/kg^oC;

c=Q/m∆T;

∆T=30-21.5=8.5^oC;

m=150+100=250 g=0.25 kg;

Q=cm∆T=4200*0.25*8.5=8925 J;

n(H2SO4)=0.15*0.3=0.045 mol;

H=8.925/0.045=198.33 kJ/mol;

Answer: 198.33 kJ/mol