ThermochemistryMedium

Question

If the enthalpy of formation and enthalpy of solution of HCl (g) are - 92.3 kJ/mol and - 75.14 kJ/mol respectively then find enthalpy of formation of Cl- (aq) :

Options

A.-17.16 kJ/mol
B.-167.44 kJ/mol
C.17.16 kJ/mol
D.None of these

Solution

HCI(g) + aq → H+ (aq.) + CI- (aq.);
ᐃrH = - 75.14 = ᐃfH (H+, aq) + ᐃfH (CI-, g) - ᐃfH (HCI, g)
ᐃfH (H+, aq) = 0
ᐃfH (CI- , aq) = - 75.14 - 92.3 = - 167.44 kJ/mol

Create a free account to view solution

View Solution Free
Topic: Thermochemistry·Practice all Thermochemistry questions

More Thermochemistry Questions

Enthalpies of solution of BaCl2(s) and BaCl2·2H2O(s) are −20.6 kJ/mol and 8.8 kJ/mol, respectively. ΔH hydration of BaCl...The standard heat of formation of carbon atom in gaseous state in kJ/mol is - ᐃHo (atomisation of CO gas) = 1072 kJ/mo...Heat absorbed in the reaction H2(g) + Cl2(g) → 2HCl(g) is 182 kJ. Bond energies of H–H = 430 kJ/mole and Cl–Cl = 242 kJ/...The standard enthalpy of formation of a substance...A solution was prepared by dissolving 7.45 g of KCl in 200 g of H2O in a calorimeter with a water equivalent of 25 g. Th...