.............
These two compounds both have molecular formula C4H8O2.
Compare properties:
...................methyl propanoate...................................................................................butanoic acid
0.909 . . . . . . . . . . . . . . . . relative density (liquid) . . . . . . . . . . . . . . . . 0.953
1.374 . . . . . . . . . . . . . . . . refractive index (liquid) . . . . . . . . . . . . . . . .1.396
79.8 . . . . . . . . . . .. . . . . . . boiling point (oC) . . . . . . . . . . . . . . . . . . .. . 163.3
- 87.5 . . . . . . . . . . . . . . . . . melting point (oC) . . . . . . . . . . . . . . . . . . . . . - 5.4
slight . . . . . . . . . . . . . . . . . . solubility in water. . . . . . . . . . . . . . . . . . . .miscible
What causes the difference in boiling point?
As is the case with acetic acid (see diagram below), hydrogen bonds form between butanoic acid molecules.
What causes the difference in solubility?
Hydrogen bonding occurs between butanoic acid molecules and water molecules.
