<p>The standard enthalpy of formation&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML" class="wrs_chemistry"><mfenced><mrow><msub><mo>&#8710;</mo><mi mathvariant="normal">f</mi></msub><msup><mi mathvariant="normal">H</mi><mo>&#176;</mo></msup></mrow></mfenced></math>&nbsp;at 298 K for methane,&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>C</mi><msub><mi>H</mi><mn>4</mn></msub><mo>(</mo><mi>g</mi><mo>)</mo></math>&nbsp;is -74.8 kJ&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>m</mi><mi>o</mi><msup><mi>l</mi><mrow><mo>-</mo><mn>1</mn></mrow></msup></math>. The additional information required to determine the average energy for C-H bond formation would be:</p>