IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Acetonitrile with Water

Components:
   (1) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail
   (2) Acetonitrile; C2H3N; [75-05-8]  NIST Chemistry WebBook for detail

Original Measurements:
   Schneider, G., Z Phys. Chem. (Munich) 41, 327 (1964).

Variables:
   Temperature = 228 K to 272 K
   Pressure = 0.1 MPa to 157 Mpa

Prepared By:
   Valerii P. Sazonov

Experimental Remarks:

   Monotectic equilibrium occurs at -10.0 °C (263.2 K, compiler).A eutectic was reported at -45.6 °C (227.6 K, compiler). Four-phase (two liquid and two solid) equilibrium is realized at -24.2 °C (249.0 K, compiler) and 125.2 MPa.Region of immiscibility disappears at -19.0 °C (254.2 K, compiler) and 156.6 MPa.

Experimental Data:   (Notes on the Nomenclature)

Table 1. Mutual solubility of acetonitrile (1) and water (2) at 0.1 Mpa
t/°C	T/K	10² * Mass Fraction w₁	Mole Fraction x₁ (compiler)	Comment(s)
-10.7 (a)	262.5	-	-	Water-rich phase
-7.4 (a)	265.8	15.7	0.077	Water-rich phase
-6.2	267.0	34.8	0.192	Water-rich phase
-4.5	268.7	-	-	Water-rich phase
-3.5	269.7	40.0	0.229	Water-rich phase
-1.2	272.0	-	-	Water-rich phase
-1.1	272.1	55.0	0.353	Water-rich phase
-10.7 (a)	262.5	90.0	0.801	Acetonitrile-rich phase
-7.4 (a)	265.8	-	-	Acetonitrile-rich phase
-6.2	267.0	-	-	Acetonitrile-rich phase
-4.5	268.7	74.9	0.571	Acetonitrile-rich phase
-3.5	269.7	-	-	Acetonitrile-rich phase
-1.2	272.0	55.3	0.356	Acetonitrile-rich phase
-1.1	272.1	55.0	0.353 (UCST)	Acetonitrile-rich phase

Table 2. Solubility temperatures of mixtures of the (1) and (2) depending on pressure
t/°C	T/K	Pressure	10² * Mass Fraction w₁	Mole Fraction x₁ (compiler)
-14.5	258.7	39.6	34.8	0.192
-18.6	254.6	73.2	34.8	0.192
-19.8	253.4	84.3	34.8	0.192
-20.7	252.5	94.9	34.8	0.192
-9.1	264.1	29.7	40.0	0.229
-13.6	259.6	59.6	40.0	0.229
-17.3	255.9	88.9	40.0	0.229
-20.0	252.2	119.2	40.0	0.229
-3.9	269.3	19.8	57.8	0.379
-4.7	268.5	24.8	57.8	0.379
-5.9	267.3	34.3	57.8	0.379
-7.9	265.3	49.5	57.8	0.379
-9.7	263.5	62.6	57.8	0.379
-9.7	263.5	64.6	57.8	0.379
-11.7	261.5	79.8	57.8	0.379
-13.0	260.2	90.9	57.8	0.379
-13.4	259.8	94.9	57.8	0.379
-17.5	255.7	140.4	57.8	0.379
-7.7	265.5	19.8	74.9	0.571
-9.8	263.4	39.4	74.9	0.571
-12.8	260.4	59.6	74.9	0.571
-14.9	258.3	78.8	74.9	0.571
-16.8	256.4	99.0	74.9	0.571
-18.5	254.7	119.2	74.9	0.571
-20.2	252.0	138.4	74.9	0.571

Notes:
   ^a  Solid-liquid equilibrium.

Method/Apparatus/Procedure:
   The synthetic method was used as reported elsewhere.¹

Source and Purity of Materials:
   (1) Fluka AG; pure grade; twice distilled; purity better than 99.8 mole %; melting point = -43.9 °C.
   (2) Twice distilled.

Estimated Errors:
   Solubility: Not reported.
   Temperature: Not reported.

References:
   1. G. Schneider, Z Phys. Chem. (Munich) 37, 333 (1963).