AB, $$A2$$ and $$B2$$ are diatomic molecules, if the bond enthalpies of $$A2$$, AB and $$B2$$ are in the ratio of $$1$$ : $$1$$ : $$0.5$$ and the enthalpy of formation of AB from $$A2$$ and $$B2$$ is $$-100$$ kJ $$mol-1$$, combustion of $$A2$$ gives AO and ∆$$HC=-1200$$ kJ $$mol-1$$. Bond energy of $$O=O$$ bond is $$500$$ kJ $$mol-1$$. What is the bond enthalpy of (A$$ $$-$$ $$O) bond ?

Question

AB, $$A2$$ and $$B2$$ are diatomic molecules, if the bond enthalpies of $$A2$$, AB and $$B2$$ are in the ratio of $$1$$ : $$1$$ : $$0.5$$ and the enthalpy of formation of AB from $$A2$$ and $$B2$$ is $$-100$$ kJ $$mol-1$$, combustion of $$A2$$ gives AO and ∆$$HC=-1200$$ kJ $$mol-1$$. Bond energy of $$O=O$$ bond is $$500$$ kJ $$mol-1$$. What is the bond enthalpy of (A$$ $$-$$ $$O) bond ?

Infinity Learn · Accepted Answer

Bond enthalpy (BE) of $$A2$$ $$=$$ x,  AB $$=$$ x and $$B2$$ $$=$$ $$x212A2+12B2$$ → AB        $$-100$$ $$kJ/mol-1$$                 .....(i) $$12A2+12O2$$ → AO        $$-1200$$ $$kJ/mol$$ (given) $$A2+O2$$ → $$2AO$$               $$-2400$$ $$kJ/mol$$           ....(ii) $$O=O$$→ $$500$$ $$kJ/mol$$ From eq. i $$12$$ B.$$EA2$$ $$+$$ $$12$$ B.$$EB2-$$ B.$$EAB=-100$$ $$12x$$ $$+$$ $$x4-x=-100$$ $$-x4=-100$$ $$x=$$ $$400$$ $$kJ/mol$$ Now, from eq. ii B.$$EA2$$ $$+$$  B.$$EO2-2$$ B.$$EAO=-2400$$ $$x++500-2$$ B.$$EAO=-2400$$ $$400$$ $$+$$ $$500$$ $$-$$ $$2$$ B.$$EAO=-2400$$ $$-$$ B.$$EA-O=-3300$$  B.$$EA-O=1650$$ $$kJ/mol$$.

Best Courses for You

Detailed Solution

courses

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

download the app

Download the App