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Thermodynamics

Question
CBSEENCH11006221

Calculate increment subscript straight r straight H to the power of 0 for the reaction 

The bond enthalpies of C - H,  O = O, C = O,  O - H and C = C bonds are 414, 499, 460 and 619 kJ mol-1 respectively. 

Solution

In the thermochemical equation,
   
four C-H bonds, one C = C bond and three O = O bonds are broken while four C = O bonds and four O - H bonds are formed. Thus
              increment subscript straight r straight H to the power of 0 space equals space sum from blank to blank of Bond space enthalpies subscript left parenthesis Reactants right parenthesis end subscript
space space space space space space space space space space space space space space space space space space space space space space space space space space minus space sum from blank to blank of Bond space left parenthesis enthalpy right parenthesis subscript left parenthesis Products right parenthesis end subscript
equals space open square brackets 4 space cross times space straight H subscript straight C space minus straight H end subscript superscript 0 space plus space straight H subscript straight C space minus straight C end subscript superscript 0 space plus space 3 straight H subscript straight O superscript 0 space equals space 0 close square brackets space
space space space space space space space space space space space space space space space space space minus space open square brackets 4 space cross times space straight H subscript straight C space equals space straight O end subscript superscript 0 space plus space 4 space cross times space straight H subscript straight O minus straight H end subscript superscript 0 space close square brackets

equals space open square brackets 4 space cross times 414 space plus space 619 space plus space 3 space cross times space 499 close square brackets
space space space space space space space space space space space space space space space space space space space space space space minus space open square brackets 4 cross times 724 space plus space 4 cross times space 460 close square brackets

space equals space 1656 space plus space 619 space plus space 1497 space minus space 2896 space minus space 1840
equals space 964 space kJ space mol to the power of negative 1 end exponent