Question

Use average bond enthalpies (linked above) to calculate the enthalpy change for the following gas-phase reaction. CO(g) + Cl2(g) COCl2(g) To analyze the reaction, first draw Lew To analyze the reaction, first draw Lewis structures for all reactant and product molecules. ΔHreaction = ------ kJ Draw the reaction using separate sketchers for each species. Separate multiple reactants and/or products using the + sign from the drop-down arrow. Separate reactants from products using the → symbol from the drop-down menu. Remember to include nonbonding valence electrons in your Lewis structures. To analyze the reaction, first draw Lewis structures for all reactant and product molecules. Draw the reaction using separate sketchers for each species. Separate multiple reactants and/or products using the + sign from the drop-down arrow. Separate reactants from products using the → symbol from the drop-down menu. Remember to include nonbonding valence electrons in your Lewis structures. To analyze the reaction, first draw Lewis structures for all reactant and product molecules. Draw the reaction using separate sketchers for each species. Separate multiple reactants and/or products using the + sign from the drop-down arrow. Separate reactants from products using the → symbol from the drop-down menu. Remember to include nonbonding valence electrons in your Lewis structures.

Answer 1

Answer:

ΔHreaction (KJ) =  - 78 KJ

The value may vary in relation to the source of the bond enthalpy data.

 Bond enthalpies used  (From a table of bond enthalpies )

Bond           KJ/ mol

C≡O           1080

C-Cl            330

C=O           741

Cl-Cl           243

Explanation:

                         CO(g) + Cl2(g)  →    COCl2(g)

1) Lewis structures

Valence electrons

C     4

O     6

Cl     7

Reactants

CO(g)

In the case of CO, carbon has a negative charge and oxygen a positive charge.

Cl2(g)

Products

COCl2(g)

_______________________

ΔHreaction (KJ) = ∑ n* ΔH ( reactants) - ∑ n* ΔH (product)

ΔHreaction (KJ) =   (ΔHC≡O +   ΔHCl-Cl)  - ( ΔHC=O  + 2* ΔHC-Cl)

Replacing the values

ΔHreaction (KJ) =   (1080 +  243)  - ( 741 + 2* 330)

ΔHreaction (KJ) = 1323 -  1401

                          =  - 78 KJ