Calculate the standard enthalpy change for the reaction between hydrochloric acid (HCl) and ammonia (NH3) to produce ammonium chloride (NH4Cl) if the reaction is carried out in a solution of water (H2O), given the following information:HCl(aq) + H2O(l) -> H3O+(aq) + Cl-(aq) ΔH1 = -74.8 kJ/mol NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH-(aq) ΔH2 = -51.8 kJ/mol NH4Cl(s) → NH4+(aq) + Cl-(aq) ΔH3 = 15.2 kJ/mol Ensure that the answer is in kJ/mol.

Question

Calculate the standard enthalpy change for the reaction between hydrochloric acid (HCl) and ammonia (NH3) to produce ammonium chloride (NH4Cl) if the reaction is carried out in a solution of water (H2O), given the following information:HCl(aq) + H2O(l) -> H3O+(aq) + Cl-(aq)  ΔH1 = -74.8 kJ/mol  NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH-(aq)   ΔH2 = -51.8 kJ/mol  NH4Cl(s) → NH4+(aq) + Cl-(aq)   ΔH3 = 15.2 kJ/m

Answer 1

To calculate the standard enthalpy change for the reaction between HCl and NH3, we need to use Hess's Law. Hess's Law states that the enthalpy change of a reaction is the same, whether it occurs in one step or several steps. We can use the given reactions to create a pathway from reactants to products and sum the enthalpy changes of each step to find the overall enthalpy change.The overall reaction we want is:HCl aq  + NH3 aq  -> NH4Cl s We can manipulate the given reactions to create this pathway:1. HCl aq  + H2O l  -> H3O+ aq  + Cl- aq   H1 = -74.8 kJ/mol2. NH3 aq  + H2O l   NH4+ aq  + OH- aq    H2 = -51.8 kJ/mol3. NH4Cl s   NH4+ aq  + Cl- aq    H3 = 15.2 kJ/molFirst, reverse reaction 3 to get Cl- aq  and NH4+ aq  on the reactant side:3. NH4+ aq  + Cl- aq   NH4Cl s    H3' = -15.2 kJ/molNow, add reactions 1, 2, and 3':1. HCl aq  + H2O l  -> H3O+ aq  + Cl- aq   H1 = -74.8 kJ/mol2. NH3 aq  + H2O l   NH4+ aq  + OH- aq    H2 = -51.8 kJ/mol3. NH4+ aq  + Cl- aq   NH4Cl s    H3' = -15.2 kJ/mol--------------------------------------------------------   HCl aq  + NH3 aq  -> NH4Cl s    H = ?Now, sum the enthalpy changes:H = H1 + H2 + H3' = -74.8 kJ/mol +  -51.8 kJ/mol  +  -15.2 kJ/mol  = -141.8 kJ/molSo, the standard enthalpy change for the reaction between HCl and NH3 to produce NH4Cl is -141.8 kJ/mol.