P-Xylene (data page)

This page provides supplementary chemical data on p-xylene.

Material Safety Data Sheet

The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the Material Safety Datasheet (MSDS) for this chemical from a reliable source and follow its directions.

• MATHESON TRI-GAS, INC.

Structure and properties

Structure and properties
Index of refraction, nD	1.4958 at 20 °C
Dielectric constant, εr	2.2 ε0 at 20 °C
Surface tension[1]	29.92 dyn/cm at 5 °C 28.27 dyn/cm at 20 °C 24.2 dyn/cm   at 60 °C
Viscosity[2]	0.7385 mPa·s at 10 °C 0.6475 mPa·s at 20 °C 0.5134 mPa·s at 40 °C 0.3519 mPa·s at 80 °C 0.2424 mPa·s at 130 °C
Solubility[3]	0.160 g/L at 0 °C 0.181 g/L at 25 °C 0.22 g/L at 40 °C

Thermodynamic properties

Phase behavior
Triple point	286.3 K (13.15 °C), ? Pa
Critical point	617 K (344 °C), 3500 kPa
Std enthalpy change of fusion, ΔfusHo	17.1 kJ/mol
Std entropy change of fusion, ΔfusSo	59.8 J/(mol·K)
Std enthalpy change of vaporization, ΔvapHo	35.7 kJ/mol at 138 °C
Std entropy change of vaporization, ΔvapSo	? J/(mol·K)
Solid properties
Std enthalpy change of formation, ΔfHosolid	? kJ/mol
Standard molar entropy, Sosolid	? J/(mol K)
Heat capacity, cp	? J/(mol K)
Liquid properties
Std enthalpy change of formation, ΔfHoliquid	−24.4 kJ/mol
Standard molar entropy, Soliquid	247 J/(mol K)
Enthalpy of combustion, ΔcHo	−4552 kJ/mol
Heat capacity, cp	181.7 J/(mol K)
Gas properties
Std enthalpy change of formation, ΔfHogas	1.796000E+04 kJ/kg-mol[4] at 25 °C
Standard molar entropy, Sogas	? J/(mol K)
Heat capacity, cp	163.2 J/(mol K) at 120 °C
van der Waals' constants[5]	a = 3134 L2 kPa/mol2 b = 0.1809 liter per mole

Vapor pressure of liquid

P in mm Hg		1	10	40	100	400	760
T in °C		−8.1	27.3	54.4	75.9	115.9	138.3

Table data obtained from CRC Handbook of Chemistry and Physics 44th ed.

log₁₀ of p-Xylene vapor pressure. Uses formula: ${\displaystyle \scriptstyle \log _{e}P_{mmHg}=}$${\displaystyle \scriptstyle \log _{e}({\frac {760}{101.325}})-9.527348\log _{e}(T+273.15)-{\frac {7637.951}{T+273.15}}+79.55720+5.748969\times 10^{-6}(T+273.15)^{2}}$ obtained from CHERIC^[4]

Distillation data

Vapor-liquid Equilibrium for p-Xylene/o-Xylene[6] P = 26.66 kPa BP Temp. °C  % by mole p-xylene liquid vapor 100.1 0.0 0.0 99.8 4.9 5.8 99.5 9.9 11.8 99.0 17.4 20.7 98.5 25.1 29.3 98.1 32.6 37.1 97.6 40.6 44.9 97.2 48.6 53.8 96.7 56.9 61.8 96.2 64.9 69.6 95.8 73.1 77.3 95.4 81.4 84.5 94.9 90.7 91.6 94.6 95.4 96.0 94.4 100.0 100.0

Vapor-liquid Equilibrium for p-Xylene/m-Xylene[6] P = 26.66 kPa BP Temp. °C  % by mole p-xylene liquid vapor 95.30 0.0 0.0 95.20 8.3 8.5 95.15 15.5 15.8 95.05 24.3 24.9 95.00 33.0 33.6 94.90 40.9 41.7 94.85 49.0 49.7 94.75 57.1 57.9 94.70 65.3 66.1 94.60 73.8 74.3 94.55 81.7 82.2 94.50 89.5 89.9 94.45 94.8 94.8 94.40 100.0 100.0

Vapor-liquid Equilibrium for p-Xylene/carbon tetrachloride[6] P = 760 mm Hg BP Temp. °C  % by mole carbon tetrachloride liquid vapor 136.4 1.7 5.9 131.1 6.3 21.6 126.2 11.1 34.9 121.8 15.7 45.3 117.6 20.3 53.9 113.5 25.2 61.6 109.8 30.1 67.9 106.2 35.1 73.1 102.7 40.5 77.9 102.2 41.3 78.7 98.1 48.5 83.6 94.4 55.8 87.6 91.1 62.9 90.8 88.0 70.1 93.4 85.2 77.2 95.4 82.6 84.0 96.9 80.0 91.1 98.4 77.6 97.7 99.7

Vapor-liquid Equilibrium for p-Xylene/Butanone[6] P = 760 mm Hg BP Temp. °C  % by mole butanone liquid vapor 129.45 4.8 20.8 125.42 7.9 31.7 123.25 10.2 38.1 116.80 16.1 51.1 112.44 21.0 59.4 105.55 30.5 71.0 101.15 38.7 75.5 95.30 50.6 85.2 93.90 54.6 87.2 89.45 67.0 91.7 86.55 77.0 94.7 85.02 81.5 95.9 84.58 83.1 96.2 80.65 97.0 994   Vapor-liquid Equilibrium for p-Xylene/Aniline[6] P = 745 mm Hg BP Temp. °C  % by mole p-xylene liquid vapor 171 7.5 37.0 165 14.0 50.0 156 26.5 67.5 148 48.5 80.0 142 72.5 89.0 140 83.0 92.0

Spectral data

UV-Vis
Spectrum
λmax	? nm
Extinction coefficient, ε	?
IR
Spectrum	NIST
Major absorption bands	793.94 cm−1
NMR
Spectrum	AIST[permanent dead link]
Proton NMR	2.296, 7.046
Carbon-13 NMR	134.66, 128.97, 20.90
MS
Spectrum	NIST
Masses of main fragments	106, 91, 77

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• Except where noted otherwise, data relate to Standard temperature and pressure.
• Reliability of data general note.