[填空题]
The enthalpies of combustion of hydrogen and2 d38dh8kjyy a carbon are qpei:7gwxo,4zi nbyx 1,n/9 r given in the data booklet. Theneq grx4n /1i bzo,:w,7xyi9 p enthalpy of formation of ethene,$C_2H_4$,from its elements is ΔH$_f^θ$=+52.0kJ mol$^{-1}$.
1.Write the thermochemical equation for the formation of ethene.
2.Calculate the enthalpy of formation of ethene, using enthalpies of combustion from section 13 (Section 14- 2025 Syllabus) of the Data Booklet. Then compare to the given value above, and comment on the difference, if any.
ΔH$_r$=+ kJ mol$^{-1}$.
Important note: The section numbers mentioned in the video solution are specific to the 2024 syllabus.
You can refer to the question stem to find the section numbers for the 2025 syllabus.