0
How do calculate the energy needed to break all the bonds in 1 mol of methane?
Wiki User
∙ 11y ago
The standard molar enthalpy change of bond dissociation (DHd° is the energy change when 1 mole of bonds is broken, the molecules and resulting fragments being in the gaseous state at 298K and a pressure of 100kPa. Introduction
- This energy refers to a specific bond in a molecule, but if a molecule has 4 of the same bond (eg the C-H bonds in methane), then different dissociation energies can occur.
CH4(g) => CH3(g) + H(g) DHd° = +427 kJ mol-1
CH3(g) => CH2(g) + H(g) DHd° = +371 kJ mol-1
So it is much more useful to know the average amount of energy needed to break a particular bond. In this case, the process of breaking all the bonds in methane ending up with gaseous atoms.
So this process could be written as:
The enthalpy change for this reaction is +1646 kJ mol-1 , so the average bond enthalpy is +1646 / 4 = +412 kJ mol-1 . They can be looked up in data tables.
It is important to stress that these are mean or average bond enthalpies. If Average bond enthalpies are used to calculate an enthalpy change, the answer will be slightly out compared to a result obtained by other methods.
-----------------------------------------------------------------------------------------------------
So if you are talking about the Mastering chem question, here is the answer.
dissociation energy of C-H bond is 410 kJ/mol and there are 4 mols of C-H bond in 1 mol of CH4
so 410kJ/mol *4 = 1640 KJ/mol
Wiki User
∙ 9y ago
Wiki User
∙ 9y agoThe bond dissociation energy for breaking all bonds in a mole of water is the energy required to break the two hydrogen bonds from the oxygen bond. The bond dissociation energy is 498 kJ/mol .
Wiki User
∙ 9y agoA single H-O bond in a water molecule contains 366 kJ/mol of energy. So in one water molecule there is 732 kJ/mol of energy. If there is one mol of H2O, then there is 732 kJ of bond energy.
Wiki User
∙ 13y agoThe Mastering Chemistry answer is 498 kj/mol.
There is only one mol of O2
Wiki User
∙ 11y agoIt is approximately similar to the energy needed to break 4 moles of C-H bonds, it is not identical in value.
Wiki User
∙ 10y ago1659 kJ/mol
Add your answer:
Earn +20 pts
What bond is formed in methane?
Methane is a molecule with covalent bonds. Then again, there are different types of bonds. To be specific, Methane is a tetrahedral molecule with covalent long single bonds.
Why is methane used for burning in gas fires?
Methane is the IUPAC name for the main constituent in natural gas (CH4). Methane stores energy in the C-H chemical bonds and this stored energy is readily released as heat through a chemical process known as combustion (burning) which is a largely exergonic reaction.
Covalent bonds conduct heat?
In a chemical reaction bonds are broken and then reformed in a different arrangement. If the reaction is exothermic, this is because the new bonds are at a lower energy level than the old ones. For example, if you burn methane in oxygen, you are breaking C-H and O-O bonds and forming C=O and H-O bonds. If you look up(in a data table) the bond energies of each of the bonds you can total up the energies of the reactants (methane and oxygen) and products (carbon dioxide and water), and you will find that there is less energy in the bonds at the end than at the beginning. That's the energy that is released as heat.
How does the burning of natural gas methane release energy?
A. methane contains tightly held electrons. B. Carbon Dioxide and H2O contain loosely held electrons. C. Bonds with loosely held electrons are converted to bonds with tightly held electrons. D. Polar covalent bonds are converted to non-polar. E. C=O and O-H bonds are converted to C-H bonds. Which one????
Where did the energy stored in butane come from?
The energy in butane, or in any compound for that matter, is stored in the chemical bonds that hold the atoms together. It takes energy to break those bonds, and then energy is released when new bonds are formed. If the energy needed for burning butane is less than the energy generated when the new bonds are formed in CO2 and H2O, then you get useful energy being produced.
What has more energy rich bonds carbon dioxide or methane?
methane
How is stored chemical energy released?
It is stored in bonds and released in energy. Energy is needed to break the chemical bonds, and energy is released when bonds are broken.
What bond is formed in methane?
Methane is a molecule with covalent bonds. Then again, there are different types of bonds. To be specific, Methane is a tetrahedral molecule with covalent long single bonds.
Is the combustion of methane an exothermic or endotermic?
Endothermic means that the net energy produced when chemical bonds reform is less that the energy required to break the original bonds. (It gets cold because it need more energy from the surrounding molecules)Exothermic means that the net energy produced is more than the required energy to break the original bonds. (it gets hot because it releases energy)Using logic and personal experiences, when you ignite something, such as methane, it burns. just the fact that it burns shows that it is releasing energy in the form of light/heat. this makes the combustion of methane Exothermic.
What is bonding energy?
A energy bond is needed when bonds are broken released when bonds are formed .
How enzymes work by?
lowering the energy needed to break bonds.
Is chemical energy a form of potential energy?
Yes, chemical energy is a form of potential energy. Chemical energy could be considered as potential energy stored in the bonds of a molecule. To use a single example, if we burn methane (CH4) in air (with oxygen, O2, it it), the result will be the formation of carbon dioxide (CO2) and water vapor (H2O). The reaction will release a lot of heat (thermal energy), and that energy came from the chemical potential energy in the bonds of the methane.
How many covalent bonds are found in methane?
there are four covalent bonds between carbon and hydrogen in methane (CH4).
What kind of reaction is the amount of energy needed to break the original bonds is less than the energy released when new bonds form?
What type of reaction requires less energy to break the original bonds than the energy released when new bonds form?
Why is methane used for burning in gas fires?
Methane is the IUPAC name for the main constituent in natural gas (CH4). Methane stores energy in the C-H chemical bonds and this stored energy is readily released as heat through a chemical process known as combustion (burning) which is a largely exergonic reaction.
Covalent bonds conduct heat?
In a chemical reaction bonds are broken and then reformed in a different arrangement. If the reaction is exothermic, this is because the new bonds are at a lower energy level than the old ones. For example, if you burn methane in oxygen, you are breaking C-H and O-O bonds and forming C=O and H-O bonds. If you look up(in a data table) the bond energies of each of the bonds you can total up the energies of the reactants (methane and oxygen) and products (carbon dioxide and water), and you will find that there is less energy in the bonds at the end than at the beginning. That's the energy that is released as heat.
What is activations energy?
Energy needed to break chemical bonds
