In which thermochemical equations would the ΔH be considered a heat of solution? 2NaHCO3 (s) →Na2CO3 (s) + H2O (g) + CO2 (g), ΔH = - 129 kJ C6H6 (s) →C6H6 (l), ΔH=+9.87 kJ NH4NO3 (s) →NH4 + (aq) + NO3 - (aq), ΔH=+25.7 kJ/mol 2C8H18 (l) + 25O2 (g) →16CO2 (g) + 18H2O (l), ΔH = -5,471 kJ/mol

NH4NO3 (s) - -> NH4 + (aq) + NO3 - (aq) H = + 25.7 kJ/mol

Explanation:

Step 1: Data given

2NaHCO3 (s) → Na2CO3 (s) + H2O (g) + CO2 (g) ΔH = - 129 kJ

C6H6 (s) → C6H6 (l) ΔH=+9.87 kJ

NH4NO3 (s) → NH4 + (aq) + NO3 - (aq) ΔH=+25.7 kJ/mol

2C8H18 (l) + 25O2 (g) → 16CO2 (g) + 18H2O (l) ΔH = -5,471 kJ/mol

Step 2:

2NaHCO3 (s) → Na2CO3 (s) + H2O (g) + CO2 (g) H = - 129 kJ:

This is the decomposition reaction of NaHCO3.

NaHCO3 will break down and form Na2CO3, H2O and CO2

⇒ the heat here is heat of decomposition

C6H6 (s) - -> C6H6 (l), H = + 9.87 kJ

In this reaction we'll not form a new product. Benzene will change phase. From its solid form to liquid benzene.

⇒ the heat here is heat of fusion

NH4NO3 (s) - -> NH4 + (aq) + NO3 - (aq) H = + 25.7 kJ/mol

When solid NH4NO3 is dossolved in water. it will dissociate in ammonium ion (NH4+) and nitrate ion (NO3-).

This reaction shows a solid dissolving in water and therefore the H represents the heat of solution.

⇒ The heat here is heat of solution

2C8H18 (l) + 25O2 (g) - -> 16CO2 (g) + 18H2O (l), H = - 5,471 kJ/mol: this is a combustion reaction

This is the combustion reaction of octane. CO2 and H2O will be produced.

⇒ The heat here is heat of combustion.