Related Experiment Video
Updated: Mar 23, 2026
09:46
Protocol for Measuring the Thermal Properties of a Supercooled Synthetic Sand-water-gas-methane Hydrate Sample
Published on: March 21, 2016
9.3K
Ab initio modelling of methane hydrate thermophysical properties
1Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 2B2, Canada. alejandro.rey@mcgill.ca.
Physical Chemistry Chemical Physics : PCCP
|March 30, 2016
Summary
This study used ab initio modeling to determine methane hydrate
Area of Science:
- Computational materials science
- Geophysics
- Chemical physics
Background:
- Methane hydrates are crucial for energy resources and climate.
- Accurate thermophysical data is needed for their study and application.
Purpose of the Study:
- To determine key thermophysical properties of methane hydrate using ab initio modeling.
- To provide atomistic thermoelastic characterization for applications.
Main Methods:
- Density functional theory (DFT) calculations.
- Analysis of elastic constants, heat capacity, compressibility, and thermal expansion.
- Assessment of structural stability using mean square displacement and radial distribution functions.
Main Results:
- Methane hydrate is elastically isotropic with bulk modulus linearly dependent on pressure.
- Multi-body interactions and water-water interactions significantly influence compressibility.
- Heat capacity is higher than ice, while thermal expansion is lower due to reduced rigidity.
Conclusions:
- Ab initio modeling provides essential atomistic thermoelastic data for methane hydrates.
- Results are vital for hydrate detection and large-scale production.
- Understanding these properties aids in predicting hydrate behavior in various conditions.
Related Concept Videos
02:37Standard Enthalpy of Formation
50.3K
Enthalpy changes are typically tabulated for reactions in which both the reactants and products are at the same conditions. A standard state is a commonly accepted set of conditions used as a reference point for the determination of properties under other different conditions. For chemists, the IUPAC standard state refers to materials under a pressure of 1 bar and solutions at 1 M and does not specify a temperature. Many thermochemical tables list values with a standard state of 1 atm. Because...
50.3K
03:24Hybridization of Atomic Orbitals I
69.2K
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
69.2K
01:20Aldehydes and Ketones with Water: Hydrate Formation
5.4K
An oxygen-based nucleophile, like water, can undergo addition reactions with aldehydes and ketones. The reaction leads to the formation of hydrates, also referred to as 1,1-diols or geminal diols.
The formation of hydrates is a reversible reaction. Hydrate formation is influenced by steric and electronic factors accompanying the alkyl substituents on the carbonyl group: The rate of hydrate formation increases with a decrease in the number of alkyl groups attached to the carbonyl carbon. Hence,...
The formation of hydrates is a reversible reaction. Hydrate formation is influenced by steric and electronic factors accompanying the alkyl substituents on the carbonyl group: The rate of hydrate formation increases with a decrease in the number of alkyl groups attached to the carbonyl carbon. Hence,...
5.4K
01:27Inductive Effects on Chemical Shift: Overview
2.5K
The protons in unsubstituted alkanes are strongly shielded with chemical shifts below 1.8 ppm. Methine, methylene, and methyl protons appear at approximately 1.7, 1.2 and 0.7 ppm, while the proton signal from methane appears at 0.23 ppm. An electronegative substituent, such as chlorine, withdraws the electron density from the protons, increasing their chemical shift. Progressive substitution of the hydrogens in methane by chlorine shifts the proton signals increasingly downfield, to 3.05 ppm in...
2.5K
02:18Conformations of Ethane and Propane
19.2K
In an organic molecule, free rotation about the carbon-carbon single bond results in energetically different conformers of the molecule. Due to this rotation, called the internal rotation, ethane has two major conformations — staggered and eclipsed.
Staggered conformation is a low energy and more stable conformation with the C-H bonds on the front carbon placed at 60°dihedral angles relative to the C-H bonds on the back carbon, leading to a reduced torsional strain. In staggered...
Staggered conformation is a low energy and more stable conformation with the C-H bonds on the front carbon placed at 60°dihedral angles relative to the C-H bonds on the back carbon, leading to a reduced torsional strain. In staggered...
19.2K
02:33Physical Properties of Alkanes
15.8K
Alkanes are nonpolar molecules due to the presence of only carbon and hydrogen atoms. The electronegativity difference between carbon and hydrogen is minimal, and hence alkanes have a zero dipole moment. This leads to the presence of only dispersion forces between the molecules. The strength of dispersion forces is dependent on the surface area of the molecules on which they act. Since the surface area increases with the molecular length for straight-chain alkanes, the dispersion forces also...
15.8K