A 100. mL sample of 0.200 M aqueous hydrochloric acid is added to 100. mL of 0.200 M aqueous ammonia in a open calorimeter having a negligible heat capactity. The following reaction occurs when the two solutions are mixed.
HCl(aq) + NH3(aq) → NH4Cl(aq)
After mixing the temperature increases 3.68 °C. Assuming that the specific heat and density of the aqueous mixture is the same as that for pure water (4.184 J/g °C and 1.00 g/mL, respectively), calculate ΔH for the reaction as written.
Answer
-154 kJ/mol
154 kJ/mol
38.5 kJ/mol
77.0 kJ/mol
-77.0 kJ/mol