A 100.0 mL sample of 0.300 mol L^-1 NaOH is mixed with a 100.0 mL sample of 0.300 mol L^-1 HNO₃ in a coffee cup calorimeter. If both solutions were initially at 35.00 °C and the temperature of the resulting solution was recorded as 37.00 °C, determine the Δ_rH° (in units of kJ mol^-1)for the neutralization reaction between aqueous NaOH and HCl. Assume 1)that no heat is lost to the calorimeter or the surroundings, and 2)that the density and the heat capacity of the resulting solution are the same as water.

Question

Quizplus · Accepted Answer

The reaction between NaOH and HNO₃ is a neutralization reaction. The total volume of the solution is 200.0 mL, and the temperature change is 2.00 °C. Using q = mcΔT, where m = 200.0 g, c = 4.18 J/g°C, and ΔT = 2.00 °C, the heat absorbed by the solution is 1672 J or 1.672 kJ. Since 0.0300 mol of NaOH reacts with 0.0300 mol of HNO₃, the ΔrH° is calculated as -1.672 kJ / 0.0300 mol = -55.7 kJ/mol.

A 1000 ML Sample of 0