Question 6.8: A quantity of 1.00 × 10² mL of 0.500 M HCl was mixed with 1....
A quantity of 1.00 × 10² mL of 0.500 M HCl was mixed with 1.00 × 10² mL of 0.500 M NaOH in a constant-pressure calorimeter of negligible heat capacity. The initial temperature of the HCl and NaOH solutions was the same, 22.50°C, and the final temperature of the mixed solution was 25.86°C. Calculate the heat change for the neutralization reaction on a molar basis:
NaOH(aq) + HCl(aq) → NaCl(aq) + H_{2}O(l)
Assume that the densities and specific heats of the solutions are the same as for water (1.00 g/mL and 4.184 J/g · °C, respectively).
Strategy Because the temperature rose, the neutralization reaction is exothermic. How do we calculate the heat absorbed by the combined solution? What is the heat of the reaction? What is the conversion factor for expressing the heat of reaction on a molar basis?
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