A constant pressure "coffee-cup" calorimeter is used to measure the heat of reaction between 0.10 L of 1.0 M NaOH and 0.10 L of 1.0 M HCl. Both solutions initially are at 24.0°C; after the solutions are mixed, the final temperature is 30.4°C. If the heat capacity of the resulting solution is assumed to be totally due to water (C_p = 75.291 J/mol•K), how much heat was evolved from the reaction per mole of limiting reactant? Assume the density of all solutions is 1.0 g/mL. (C = 75.291 J/mol.K for H₂O; q = C_cal$\Delta$T)

Question

Quizplus · Accepted Answer

The heat evolved (q) can be calculated using q = mCΔT, where m is the mass of the solution (200 g), C is the specific heat capacity (4.18 J/g°C), and ΔT is the temperature change (6.4°C). The heat evolved is then divided by the number of moles of the limiting reactant (0.1 mol) to find the heat per mole.

A Constant Pressure "Coffee-Cup" Calorimeter Is Used to Measure the Heat