All Courses
Explore Courses UPSC Exam UPSC Test Series Free Notes EduRev Infinity Get the App Login Join for Free
Sign in Open App
JEE Exam  >  JEE Questions  >  The standard enthalpy of formation (fHº2... Start Learning for Free
SaveJoin the Discussion on the App
The standard enthalpy of formation (∆fHº298) for methane, CH4 is– 74.9 kJ mol–1. In order to calculate the average energy given out in the formation of a C–H bond from this it is necessary to know which one of the following?
  • a)
    the dissociation energy of the hydrogen molecule, H2
  • b)
    the first four ionisation energies of carbon
  • c)
    the dissociation energy of H2 and enthalpy of sublimation of carbon (graphite)
  • d)
    the first four ionisation energies of carbon and electron affinity of hydrogen
Correct answer is option 'C'. Can you explain this answer?
FREE This question is part of
Download PDF Attempt Test
Download PDF Attempt this Test
Verified Answer
The standard enthalpy of formation (fHº298) for methane, CH4 is&n...
Write the expression of the balanced chemical equation for the formation of methane.

If the values of enthalpy of sublimation of carbon and bond dissociation energy of H2 are known, the average energy released in the given reaction can be calculated.
View all questions of this test
Most Upvoted Answer
The standard enthalpy of formation (fHº298) for methane, CH4 is&n...
°) of a compound is the change in enthalpy that occurs when one mole of the compound is formed from its constituent elements in their standard states under standard conditions (25°C and 1 atm pressure). The standard enthalpy of formation is usually denoted as ΔfH°.

For example, the standard enthalpy of formation of water (H2O) is -285.83 kJ/mol. This means that when one mole of water is formed from its constituent elements (hydrogen and oxygen) under standard conditions, 285.83 kJ of heat is released.

Standard enthalpy of formation values are useful in calculating the enthalpy changes of chemical reactions. By subtracting the enthalpies of formation of the reactants from the enthalpies of formation of the products, we can determine the overall enthalpy change of the reaction.

It is important to note that the standard enthalpy of formation values are only valid at standard conditions. At different temperatures and pressures, the enthalpy of formation will be different.
< Previous Question Next Question >
Explore Courses for JEE exam

Similar JEE Doubts

Properties, whose values depend only on the concentration of solute particles in solution and not on the identity of the solute are called colligative properties. There may be change in number of moles of solute due to ionisation or association hence these properties are also affected. Number of moles of the product is related to degree of ionisation or association by vant Hoff factor ‘i’ given by i = [ 1 + (n – 1) α] for dissociationwhere n is the number of products (ions or molecules) obtained per mole of the reactant & i = for association.Where n is number of reactant particles associated to give 1 mole product.A dilute solution contains ‘t’ moles of solute X in 1 Kg of solvent with molal elevation constant Kb. The solute dimerises in the solution according to the following equation. The degree of association is α.Q.The vant Hoff factor will be [ if we start with one mole of X ]

Properties, whose values depend only on the concentration of solute particles in solution and not on the identity of the solute are called colligative properties. There may be change in number of moles of solute due to ionisation or association hence these properties are also affected. Number of moles of the product is related to degree of ionisation or association by vant Hoff factor ‘i’ given by i = [ 1 + (n – 1) α] for dissociationwhere n is the number of products (ions or molecules) obtained per mole of the reactant & i = for association.Where n is number of reactant particles associated to give 1 mole product.A dilute solution contains ‘t’ moles of solute X in 1 Kg of solvent with molal elevation constant Kb. The solute dimerises in the solution according to the following equation. The degree of association is α.Q.The colligative properties observed will be

Properties, whose values depend only on the concentration of solute particles in solution and not on the identity of the solute are called colligative properties. There may be change in number of moles of solute due to ionisation or association hence these properties are also affected. Number of moles of the product is related to degree of ionisation or association by vant Hoff factor ‘i’ given by i = [ 1 + (n – 1) α] for dissociationwhere n is the number of products (ions or molecules) obtained per mole of the reactant & i = for association.Where n is number of reactant particles associated to give 1 mole product.A dilute solution contains ‘t’ moles of solute X in 1 Kg of solvent with molal elevation constant Kb. The solute dimerises in the solution according to the following equation. The degree of association is α.Q.The equilibrium constant for the process can be expressed as

Top Courses for JEEView all

Top Courses for JEE

The standard enthalpy of formation (fHº298) for methane, CH4 is– 74.9 kJ mol–1. In order to calculate the average energy given out in the formation of a C–H bond from this it is necessary to know which one of the following?a)the dissociation energy of the hydrogen molecule, H2b)the first four ionisation energies of carbonc)the dissociation energy of H2 and enthalpy of sublimation of carbon (graphite)d)the first four ionisation energies of carbon and electron affinity of hydrogenCorrect answer is option 'C'. Can you explain this answer?
Question Description
The standard enthalpy of formation (fHº298) for methane, CH4 is– 74.9 kJ mol–1. In order to calculate the average energy given out in the formation of a C–H bond from this it is necessary to know which one of the following?a)the dissociation energy of the hydrogen molecule, H2b)the first four ionisation energies of carbonc)the dissociation energy of H2 and enthalpy of sublimation of carbon (graphite)d)the first four ionisation energies of carbon and electron affinity of hydrogenCorrect answer is option 'C'. Can you explain this answer? for JEE 2024 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about The standard enthalpy of formation (fHº298) for methane, CH4 is– 74.9 kJ mol–1. In order to calculate the average energy given out in the formation of a C–H bond from this it is necessary to know which one of the following?a)the dissociation energy of the hydrogen molecule, H2b)the first four ionisation energies of carbonc)the dissociation energy of H2 and enthalpy of sublimation of carbon (graphite)d)the first four ionisation energies of carbon and electron affinity of hydrogenCorrect answer is option 'C'. Can you explain this answer? covers all topics & solutions for JEE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The standard enthalpy of formation (fHº298) for methane, CH4 is– 74.9 kJ mol–1. In order to calculate the average energy given out in the formation of a C–H bond from this it is necessary to know which one of the following?a)the dissociation energy of the hydrogen molecule, H2b)the first four ionisation energies of carbonc)the dissociation energy of H2 and enthalpy of sublimation of carbon (graphite)d)the first four ionisation energies of carbon and electron affinity of hydrogenCorrect answer is option 'C'. Can you explain this answer?.
Solutions for The standard enthalpy of formation (fHº298) for methane, CH4 is– 74.9 kJ mol–1. In order to calculate the average energy given out in the formation of a C–H bond from this it is necessary to know which one of the following?a)the dissociation energy of the hydrogen molecule, H2b)the first four ionisation energies of carbonc)the dissociation energy of H2 and enthalpy of sublimation of carbon (graphite)d)the first four ionisation energies of carbon and electron affinity of hydrogenCorrect answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for JEE. Download more important topics, notes, lectures and mock test series for JEE Exam by signing up for free.
Here you can find the meaning of The standard enthalpy of formation (fHº298) for methane, CH4 is– 74.9 kJ mol–1. In order to calculate the average energy given out in the formation of a C–H bond from this it is necessary to know which one of the following?a)the dissociation energy of the hydrogen molecule, H2b)the first four ionisation energies of carbonc)the dissociation energy of H2 and enthalpy of sublimation of carbon (graphite)d)the first four ionisation energies of carbon and electron affinity of hydrogenCorrect answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of The standard enthalpy of formation (fHº298) for methane, CH4 is– 74.9 kJ mol–1. In order to calculate the average energy given out in the formation of a C–H bond from this it is necessary to know which one of the following?a)the dissociation energy of the hydrogen molecule, H2b)the first four ionisation energies of carbonc)the dissociation energy of H2 and enthalpy of sublimation of carbon (graphite)d)the first four ionisation energies of carbon and electron affinity of hydrogenCorrect answer is option 'C'. Can you explain this answer?, a detailed solution for The standard enthalpy of formation (fHº298) for methane, CH4 is– 74.9 kJ mol–1. In order to calculate the average energy given out in the formation of a C–H bond from this it is necessary to know which one of the following?a)the dissociation energy of the hydrogen molecule, H2b)the first four ionisation energies of carbonc)the dissociation energy of H2 and enthalpy of sublimation of carbon (graphite)d)the first four ionisation energies of carbon and electron affinity of hydrogenCorrect answer is option 'C'. Can you explain this answer? has been provided alongside types of The standard enthalpy of formation (fHº298) for methane, CH4 is– 74.9 kJ mol–1. In order to calculate the average energy given out in the formation of a C–H bond from this it is necessary to know which one of the following?a)the dissociation energy of the hydrogen molecule, H2b)the first four ionisation energies of carbonc)the dissociation energy of H2 and enthalpy of sublimation of carbon (graphite)d)the first four ionisation energies of carbon and electron affinity of hydrogenCorrect answer is option 'C'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice The standard enthalpy of formation (fHº298) for methane, CH4 is– 74.9 kJ mol–1. In order to calculate the average energy given out in the formation of a C–H bond from this it is necessary to know which one of the following?a)the dissociation energy of the hydrogen molecule, H2b)the first four ionisation energies of carbonc)the dissociation energy of H2 and enthalpy of sublimation of carbon (graphite)d)the first four ionisation energies of carbon and electron affinity of hydrogenCorrect answer is option 'C'. Can you explain this answer? tests, examples and also practice JEE tests.
Explore Courses for JEE exam

Top Courses for JEE

Explore Courses

Suggested Free Tests

Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev
Get App
© EduRev
Education Revolution
Follow Us
Signup to see your scores go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup