Problem summary
100 g hydrochloric acid was mixed with 100 g of aqueous sodium hydroxide.
The initial temperature of both solutions was 23.79°C. The temperature of the mixture was 31.56°C.
Calculate the heat of reaction assuming that the the temperature change of the vessel in which the reaction is carried out can be ignored.
c(solution) = 4.184 J K-1 g-1
HCl(aq) + NaOH(aq)
NaCl(aq) + H2O
The initial temperature of both solutions was 23.79°C. The temperature of the mixture was 31.56°C.
Calculate the heat of reaction assuming that the the temperature change of the vessel in which the reaction is carried out can be ignored.
c(solution) = 4.184 J K-1 g-1
HCl(aq) + NaOH(aq)
NaCl(aq) + H2OΔT = 31.56°C - 23.79°C = 7.77°C = 7.77 K
q(surroundings) = q(mixed solution)
q(surroundings) = = q(mixed solution) = c(mixed solution) × m(mixed solution) × ΔT
q(mixed solution) = 4.184 Jg-1 K-1 x 200 g × 7.77 K= +6502 J
q(surroundings) = q(mixed solution)
q(surroundings) = = q(mixed solution) = c(mixed solution) × m(mixed solution) × ΔT
q(mixed solution) = 4.184 J
Calculate q(surroundings).
q(system) = q(reaction) = -q(surroundings)
q(system) = q(reaction) = -6502 J
q(system) = q(reaction) = -6502 J
Assume that heat transfer is complete.