Consider two-step neutralization reaction of solid metal hydroxide MOH with an acid. The formation enthalpy of MOH is -438.15 kJ/mol and for M+ it is -249.07 kJ /mol. What is the enthalpy of dissociation? kJ/mol What is the enthalpy of neutralization of an aqueous solution of solid metal hydroxide MOH with an acid? kJ/mol
Thermochemistry
Thermochemistry can be considered as a branch of thermodynamics that deals with the connections between warmth, work, and various types of energy, formed because of different synthetic and actual cycles. Thermochemistry describes the energy changes that occur as a result of reactions or chemical changes in a substance.
Exergonic Reaction
The term exergonic is derived from the Greek word in which ‘ergon’ means work and exergonic means ‘work outside’. Exergonic reactions releases work energy. Exergonic reactions are different from exothermic reactions, the one that releases only heat energy during the course of the reaction. So, exothermic reaction is one type of exergonic reaction. Exergonic reaction releases work energy in different forms like heat, light or sound. For example, a glow stick releases light making that an exergonic reaction and not an exothermic reaction since no heat is released. Even endothermic reactions at very high temperature are exergonic.
![The heat of neutralization of solid metal hydroxide with an aqueous solution of an acid
might be determined directly in a one-step reaction
МОН(s) + H* M'+ H-0(1)
or indirectly using a two-step reaction
МОН(s) —> М* + он
ОН + Н
H2O(1)
Based on the net ionic equation of the reaction, the theoretical enthalpy of reaction,
AHîheo!
liheo kJ/mol], can be found from the enthalpies of formation as
ΔΗλ ΔΗ; ΗΟ() + ΔΗ Μ' (αq)] -ΔΜΟH (s)]|
Based on the measured change in temperature, AT[K], and the heat capacity of the cup,
Ccup[J/K], the experimental enthalpy of reaction, AHap[kJ/mol], can
found as
AHerp
(S„ Viot + Ceup) AT/nL.R.,
where Vtot [mL] is the total volume of the solution, nL.R.[mmol] is the amount of the
limiting reagent, and specific heat of water is s, = 4.18 JML¯!K¯l
The percent error can be found according to the formula
AH-AHtheo x 100%
%E =
exp
AHiheo
Using the values for standard enthalpies of formation from the table 8-1 find the enthalpies
for the reactions in the following questions.
Question 1
Consider two-step neutralization reaction of solid metal hydroxide MOH with an
acid. The formation enthalpy of MOH is -438.15 kJ/mol and for Mt it is
-249.07 kJ/mol. What is the enthalpy of dissociation?
kJ/mol
What is the enthalpy of neutralization of an aqueous solution of solid metal hydroxide
MOH with an acid?
kJ/mol](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F1a88c37e-6615-4150-bb38-f5623b75f939%2F6721c784-e1e6-466f-a123-6b51c0c98e7c%2Fo9sxt7f_processed.jpeg&w=3840&q=75)
Trending now
This is a popular solution!
Step by step
Solved in 4 steps
