06.04.2013 Views

LANGE'S HANDBOOK OF CHEMISTRY

LANGE'S HANDBOOK OF CHEMISTRY

LANGE'S HANDBOOK OF CHEMISTRY

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

TABLE 11.9 Molecular Elevation of the Boiling Point<br />

Ebullioscopic constants.<br />

Molecular weights can be determined with the relation:<br />

PRACTICAL LABORATORY INFORMATION 11.13<br />

1000 w 2<br />

M E b w T<br />

1 b<br />

where T b is the elevation of the boiling point brought about by the addition of w 2 grams of solute to w 1 grams<br />

of solvent and E b is the ebullioscopic constant. In the column headed “Barometric correction” is the number of<br />

degrees for each millimeter of difference between the barometric reading and 760 mmHg to be subtracted from<br />

E b if the pressure is lower, or added if higher, than 760 mm. In general, the effect is within experimental error<br />

if the pressure is within 10 mm of 760 mm.<br />

The ebullioscopic constant, a characteristic property of the solvent, may be calculated from the relation:<br />

E <br />

b<br />

2 RTb M<br />

H<br />

vap<br />

where R is the molar gas constant, M is the molar mass of the solvent, and vapH the molar enthalpy (heat) of<br />

vaporization of the solvent.<br />

Compound<br />

Barometric<br />

correction<br />

E b,<br />

C kg·mol 1<br />

Acetic acid 0.0008 3.22<br />

Acetic anhydride 3.79<br />

Acetone 0.0004 1.80<br />

Acetonitrile 1.44<br />

Acetophenone 5.81<br />

Aniline 0.0009 3.82<br />

Benzaldehyde 4.24<br />

Benzene 0.0007 2.64<br />

Benzonitrile 4.02<br />

Bromobenzene 0.0016 6.35<br />

Bromoethane 1.73<br />

1-Butanol 2.17<br />

2-Butanone 2.28<br />

cis-2-Butene-1,4-diol 2.73<br />

D-()-Camphor 0.0015 4.91<br />

Carbon disulfide 0.0006 2.42<br />

Carbon tetrachloride 0.0013 5.26<br />

Chlorobenzene 0.0011 4.36<br />

1-Chlorobutane 3.13<br />

Chloroethane 1.77<br />

Chloroform 0.0009 3.80<br />

Cyclohexane 0.0007 2.92<br />

Cyclohexanol 3.5<br />

Decane 6.10<br />

1,2-Dibromomethane 0.0016 6.01<br />

1,1-Dichloroethane 3.13<br />

1,2-Dichloroethane 3.27<br />

Dichloromethane 2.42<br />

Diethyl ether 0.0005 2.20<br />

Diethyl sulfide 3.14<br />

Dimethoxymethane 2.12<br />

N,N-Dimethylacetamide 3.22<br />

Dimethyl sulfide 1.85<br />

Dimethyl sulfoxide 3.22

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!