Chemistry - Thermochemistry Question with Solution | TestHub
Two solutions, initially at 25°C, were mixed in an insulated bottle. One contained 200 ml of 0.4 M weak monoprotic acid solution. The other contained 100 ml of a solution having 0.5 mole NaOH per litre. After mixing, the temperature rose to 26°C. Assume that the densities of both the solutions are 1.0 g/ml and that their specific heat capacities are all 1.0 cal/g-K. The amount of heat evolved (in kcal) in the neutralization of 1 mole of the acid is
Answer:
Solution:
The limiting reactant is NaOH.
The moles of NaOH are calculated as 0.1 M × 0.5 L = 0.05 mol.
The moles of acid are 0.08 mol, which means the acid is in excess.
The heat generated is 300 cal for 0.05 mol of NaOH neutralized.
To find the heat per mole, we calculate:
300 cal/0.05 mol = 6000 cal/mol = 6 kcal/mol
The answer is 6.
