IUPAC-NIST Solubility Database
NIST Standard Reference Database 106


Glass Ball as Bullet Solubility System: Rubidium formate with Water

Components:
   (1) Rubidium formate; RbCHO2; [3495-35-0]  NIST Chemistry WebBook for detail
   (2) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Sidgwick, N.V.; Gentle, J.A.H.R., J. Chem. Soc. 121, 1837 (1922).

Variables:
   Temperature = -1.82 ºC to -170 ºC

Prepared By:
   Chr. Balarew and St. Trendafilova

Experimental Remarks:

   The molality values were calculated by the compilers.

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)
  
Composition of equilibrium liquid phase
t/°CPhaseMass Fraction w1100 * Mole Fraction1m1 [mol kg-1]Solid Phase(s)c
-1.82Liquid6.230.9090.509A
-5.62Liquid15.932.5491.452A
-7.82Liquid20.623.4631.991A
-10.62Liquid25.794.5732.663A
-13.88Liquid30.625.7443.382A
+3.3Liquid78.8633.9728.59B
7.8Liquid80.7136.5932.06B
9.5Liquid81.3737.5933.47B
14.0Liquid83.5941.0939.04B
16.3Liquid84.6143.1242.13B
16.5Liquid---------B + C        
28.3Liquid85.645.145.6C
43.6Liquid87.7749.7555.00C
49.9Liquid89.2353.3463.49C
46.9(a)Liquid89.2353.3463.49D
51.0Liquid---------C + D         
60.8Liquid90.0655.5569.43D
101.7Liquid93.8967.95117.8D
170.0(b)Liquid100100---D
Notes:
   a  Metastable point.
   b  Melting point.
   c  The solid phases are: A = ice; B = RbCHO2•H2O; C = RbCHO2•0.5H2O; D = RbCHO2.

Method/Apparatus/Procedure:
   The freezing points were measured in a Beckmann apparatus. Analysis was done gravimetrically by evaporating the solution to dryness. At higher temperatures mixtures were sealed in tubes and the temperature at which the last crystal disappeared on warming was observed.

Source and Purity of Materials:
   The rubidium formate was prepared by neutralizing the carbonate with formic acid. Commercial 80% formic acid was distilled in a vacuum at 70 °C with enough sulfuric acid to remove the water.

Estimated Errors:
   Solubility: No information is given.
   Temperature: No information is given.