Acetonitrile (data page)

This page provides supplementary chemical data on acetonitrile.

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.

Structure and properties

More information Structure and properties ...

Structure and properties
Dielectric constant, ε_r	36.64 ε₀ at 20 °C ^[1]
Surface tension^[2]	29.29 dyn/cm

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Thermodynamic properties

More information Phase behavior, Solid properties ...

Phase behavior
Triple point^[3]	229.32 K (−43.83 °C), 167 Pa
Std entropy change of fusion, Δ_fusS^o	35.61 J/(mol·K) (crystal I → liq)
Std entropy change of vaporization, Δ_vapS^o	111.44 J/(mol·K) at 25 °C
Solid properties
Heat capacity, c_p	92.36 J/(mol K)at 298.15 K
Std enthalpy change of state transition, Δ_trsH^o	0.8979 kJ/mol at −56.2 °C (crystal II → crystal I)
Std entropy change of state transition, Δ_trsS^o	4.14 J/(mol·K) at −56.2 °C (crystal II → crystal I)
Liquid properties
Std enthalpy change of formation, Δ_fH^o_liquid	−40.56 kJ/mol
Standard molar entropy, S^o_liquid	149.62 J/(mol K)
Enthalpy of combustion, Δ_cH^o	−1256.33 kJ/mol
Heat capacity, c_p	91.7 J/(mol K) at 25 °C
Gas properties
Std enthalpy change of formation, Δ_fH^o_gas	−74.04 kJ/mol

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Vapor pressure of liquid

P in mm Hg		1	10	40	100	400	760
T in °C		−47.0_(s)	−16.3	7.7	27.0	62.5	81.8

Table data obtained from CRC Handbook of Chemistry and Physics, 44th ed. The "(s)" notation indicates temperature of solid/vapor equilibrium. Otherwise the data is temperature of liquid/vapor equilibrium.

**log₁₀ of Acetonitrile vapor pressure.** Uses formula $\scriptstyle \log _{e}P_{mmHg}=$ $\scriptstyle \log _{e}({\frac {760}{101.325}})-3.881710\log _{e}(T+273.15)-{\frac {4999.618}{T+273.15}}+41.05901+3.515956\times 10^{-06}(T+273.15)^{2}$ obtained from CHERIC^[2]

Distillation data

More information BPTemp. °C, % by mole acetonitrile ...

BP Temp. °C	% by mole acetonitrile
Vapor-liquid Equilibrium for Acetonitrile/Water^[4] P = 760 mmHg
BP Temp. °C	liquid	vapor
86.5	2.9	26.3
81.1	9.3	50.5
80.0	14.2	55.9
78.6	25.4	61.7
77.4	40.2	65.5
76.7	50.7	66.4
76.6	52.7	67.3
76.0	71.8	72.8
76.6	83.9	78.0
76.8	85.6	76.1
80.4	98.6	94.5

BP Temp. °C	% by mole methanol
Vapor-liquid Equilibrium for Acetonitrile/Methanol^[4] P = 760 mmHg
BP Temp. °C	liquid	vapor
79.20	2.5	9.5
77.95	4.0	13.5
76.77	5.5	17.5
75.12	9.7	26.5
73.12	14.0	33.0
72.07	17.0	37.5
70.96	20.0	420
68.85	24.7	45.5
68.39	28.9	50.5
66.00	41.5	59.5
65.35	47.0	62.5
64.75	54.5	65.5
64.34	63.0	71.5
64.03	69.0	74.5
63.80	74.5	78.9
63.77	82.5	82.5
63.76	86.0	86.0
63.87	90.0	88.0
64.05	93.0	91.5
64.18	95.0	93.0
64.40	97.0	95.5

BP Temp. °C	% by mole benzene
Vapor-liquid Equilibrium for Acetonitrile/Benzene^[4] P = 760 mmHg
BP Temp. °C	liquid	vapor
80.6	2.0	4.8
80.4	2.7	6.2
79.0	5.6	12.5
78.5	6.5	14.7
78.0	7.7	16.5
76.0	17.6	29.3
74.9	24.2	35.5
74.4	29.9	39.3
73.8	37.1	43.8
73.7	38.0	44.9
73.4	44.0	48.5
73.2	51.3	51.9
73.0	52.94	52.94
73.2	58.1	54.5
73.4	66.5	60.0
73.8	71.3	62.6
74.0	76.7	65.7
74.4	79.0	68.0
76.3	92.0	80.1

BP Temp. °C	% by mole toluene
Vapor-liquid Equilibrium for Acetonitrile/Toluene^[4] P = 760 mmHg
BP Temp. °C	liquid	vapor
81.5	3.3	5.1
81.4	6.9	8.1
81.1	12.18	12.18
81.3	18.2	15.4
81.4	22.1	17.2
81.8	28.4	19.5
82.7	37.5	23.0
84.4	53.3	28.4
85.6	60.5	31.5
91.1	78.5	41.7
93.4	84.0	47.3
95.6	87.6	52.6
101.2	92.9	66.5
103.6	95.6	73.8
106.7	97.7	83.6
107.5	98.2	85.4

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Spectral data

More information UV-Vis, IR ...

UV-Vis

λ_max

? nm

Extinction coefficient, ε

?

IR

Major absorption bands^[5]

Wave number	transmittance
(liquid film)
3675 cm⁻¹	79%
3544 cm⁻¹	81%
3202 cm⁻¹	77%
3164 cm⁻¹	60%
3003 cm⁻¹	52%
2944 cm⁻¹	52%
2629 cm⁻¹	81%
2410 cm⁻¹	81%
2293 cm⁻¹	44%
2254 cm⁻¹	4%
1445 cm⁻¹	30%
1378 cm⁻¹	25%
1181 cm⁻¹	84%
1040 cm⁻¹	43%
918 cm⁻¹	47%
750 cm⁻¹	70%