Input interpretation
methane
Chemical names and formulas
formula | CH_4 name | methane alternate names | biogas | fire damp | Freon 50 | marsh gas | methyl hydride | R-50 | carbane mass fractions | C (carbon) 74.9% | H (hydrogen) 25.1%
Lewis structure
Draw the Lewis structure of methane. Start by drawing the overall structure of the molecule: Count the total valence electrons of the carbon (n_C, val = 4) and hydrogen (n_H, val = 1) atoms: n_C, val + 4 n_H, val = 8 Calculate the number of electrons needed to completely fill the valence shells for carbon (n_C, full = 8) and hydrogen (n_H, full = 2): n_C, full + 4 n_H, full = 16 Subtracting these two numbers shows that 16 - 8 = 8 bonding electrons are needed. Each bond has two electrons, so the above diagram has all the necessary bonds. There are 4 bonds and hence 8 bonding electrons in the diagram. Lastly, fill in the remaining unbonded electrons on each atom. In total, there remain 8 - 8 = 0 electrons left to draw and the diagram is complete: Answer: | |
3D structure
3D structure
Basic properties
molar mass | 16.04 g/mol phase | gas (at STP) melting point | -182.47 °C boiling point | -161.48 °C density | 6.67151×10^-4 g/cm^3 (at 20 °C) solubility in water | soluble dielectric constant | 1.001
Gas properties (at STP)
density | 6.67151×10^-4 g/cm^3 (at 20 °C) vapor density | 0.55 (relative to air) molar volume | 24047 cm^3/mol surface tension | 0.0137 N/m refractive index | 1.0004478 dynamic viscosity | 1.114×10^-5 Pa s (at 25 °C)
Units
Thermodynamic properties
specific heat capacity c_p | gas | 2.225 J/(g K) | liquid | 3.481 J/(g K) molar heat capacity c_p | gas | 35.7 J/(mol K) | liquid | 55.85 J/(mol K) specific free energy of formation Δ_fG° | gas | -3.179 kJ/g molar free energy of formation Δ_fG° | gas | -51 kJ/mol specific heat of formation Δ_fH° | gas | -4.65 kJ/g molar heat of formation Δ_fH° | gas | -74.6 kJ/mol specific entropy S° | gas | 11.59 J/(g K) molar entropy S° | gas | 186 J/(mol K) molar heat of vaporization | 8.19 kJ/mol | specific heat of vaporization | 0.511 kJ/g | molar heat of combustion | 891 kJ/mol | specific heat of combustion | 55.5 kJ/g | molar heat of fusion | 0.94 kJ/mol | specific heat of fusion | 0.059 kJ/g | thermal conductivity | 0.03327 W/(m K) | critical temperature | 190 K | critical pressure | 4.599 MPa | (at STP)
Phase diagram
Phase diagram
Units
