Melting Temperature Hydrocarbons Alkane Alkene Benzene Aromatic Alcohol Acid Naphthalene

Overview

Engineering reference data for Melting Temperature Hydrocarbons Alkane Alkene Benzene Aromatic Alcohol Acid Naphthalene in thermodynamics.

Key Formulas

First Law

$\Delta U = Q - W$

Energy is conserved — heat added minus work done.

Ideal Gas Law

$PV = nRT$

Relates pressure, volume, and temperature of an ideal gas.

Heat Transfer

$Q = mc\Delta T$

Sensible heat transfer.

Carnot Efficiency

$\eta = 1 - T_C/T_H$

Maximum efficiency between two temperatures.

Variables

Symbol	Description	Unit
$U$	Internal energy	J
$Q$	Heat	J
$W$	Work	J
$P$	Pressure	Pa
$V$	Volume	m³
$T$	Temperature	K

Melting Point Data

Compound Definitions

Compound	Formula	Description
Alkane	$C_nH_{2n+2}$	Acyclic saturated hydrocarbon (paraffin)
Alkene	$C_nH_{2n}$	Unsaturated hydrocarbon with at least one C=C double bond (olefin)
Alkyne	$C_nH_{2n-2}$	Unsaturated hydrocarbon with at least one C≡C triple bond (acetylene)
Cycloalkane	$C_nH_{2n}$	Monocyclic saturated hydrocarbon (naphthene)
Cycloalkene	$C_nH_{2n-2}$	Alkene with a closed ring, non-aromatic (cycloolefin)
Benzene	$C_6H_6$	Simplest aromatic hydrocarbon, one ring
Naphthalene	$C_{10}H_8$	Two-ring aromatic hydrocarbon
Alkyl group	$C_nH_{2n+1}$	Alkane substituent missing one hydrogen

Boiling Point Trends

For hydrocarbons with the same carbon number, boiling points increase in this order:

$\text{multisubstituted alkane} < \text{single-substituted alkane} < \text{single-substituted alkene} < \text{normal alkene} < \text{normal alkane}$

$< \text{alkyl cyclohexane} < \text{alkylbenzene} < \text{cycloalkene} < \text{cycloalkane}$

$< \text{2-, 4-, 3-alkanol / 1-alkylnaphthalene} < \text{1-alkanol} < \text{normal alkanoic acid}$

Note: Melting point trends are more variable with increasing carbon number compared to boiling points, as molecular symmetry and crystal packing efficiency significantly influence solid-phase transitions.

Interactive Charts

References

• Original Source