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Enthalpy of Reactions

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Wize University Chemistry Textbook > Thermodynamics: Part 1: (0th law, 1st law, Calorimetry, Enthalpy)

Heats of Formation Method

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Practice: Formation Reaction

Write a reaction for the heat of formation for dimethylaminopyridine, (CH3)2NC5H4N.

More Heats of Formation Method Questions:
Find the standard molar enthalpy of combustion of C2H5OH using the standard enthalpy of formations below.
ΔHf(C2H5OH(l))=−277.7 kJ/mol\Delta H_f(C_2H_5OH_{(l)}) = -277.7\ kJ/mol
ΔHf(CO2(g))=−393.5 kJ/mol\Delta H_f(CO_{2(g)}) = -393.5\ kJ/mol
The standard enthalpy of formation for the amino acid glycine C2H5NO2(s) is –528 kJ/mol at 25°C. Which reaction below has an enthalpy change equal to this value?
Which of the following represents a proper formation reaction for the product indicated? (select all that apply)
Liquification of fuels is an important process that allows fuel to be transported more safely and more easily around the world. Oxidizing methane transforms it from a gas to a liquid, methanol, which is much easier to transport. Using the data provided calculate ΔH\Delta Hfor the oxidation of methane (CH4) shown below
CH4(g) + 1/2 O2(g)→CH3OH(l)ΔHfo(CH4(g))=−74.9kJ mol−1ΔHfo(CH3OH(l)=−238.6 kJ mol−1\begin{array}{c} CH_{4(g)}\ +\ 1/2\ O_{2(g)} \rightarrow CH_3OH_{(l)} \\ \\ \Delta H^o_f(CH_{4(g)})=-74.9 kJ\ mol^{-1} \\ \Delta H_f^o(CH_3OH_{(l)}=-238.6\ kJ\ mol^{-1} \end{array}
Heats of Formation

Heats of Formation
How much heat is required for the following reaction to go given that we start with 37g of CO2(g)?
CO2(g) + 2H2O(l) --> CH4(g) + 2O2(g) ∆H= +890.4kJ/mol
Heats of Formation

Enthalpy of Formation
Calculate ΔHf\Delta H_f of SO2SO_2
S+1.5O2→SO3ΔH=−395.8kJ2SO2+O2→2SO3ΔH=−198.2kJ\begin{array}{}S+1.5 O_2\rightarrow SO_3\quad \Delta H=-395.8 kJ\\2SO_2+O_2\rightarrow 2SO_3\quad \Delta H=-198.2kJ\end{array}
Find ΔHo for the following reaction if 12.0 g of N2H4 is consumed in excess N204.
2N2H4(l)+N2O4(g)→3N2(g)+4H2O(l)2N_2H_{4(l)}+N_2O_{4(g)}\to 3N_{2(g)}+4H_2O_{(l)}
The following enthalpies of formation are provided:
Find the ΔH for the atomization of gaseous propane (CH3CH2CH3). The bond enthalpy for C-H bonds is 414 kJ/mol and the bond enthalpy for C-C bonds is 347 kJ/mol.
Please report your answer to four significant figures in kJ/mol. Do NOT include units in the answer field