102k views
3 votes
Which compound in each of the following pairs would be more soluble in water?

a. CH3---CH2___CH3 or CH3---CH2---CHO
b. Propanae or 3 hexanon
c. Butanal or hexanal

User Jpsimons
by
4.3k points

1 Answer

5 votes

Answer:

a. Propanol

b. Propanone

c. Butanal

Step-by-step explanation:

From the given information:

We are to state which of the given samples are more soluble in water.

The solubility of an organic molecule in water depends on the polarity of the given organic molecule. This solubility behaviour conforms with the general rule -"like dissolve like". Solubility is a means of comparing the extent to which different solutes can dissolve in a particular solvent at a definite temperature. Water is a polar solvent; therefore, an organic molecule that will also dissolve in water must be polar.

From the first pair, we have propane and propanol.

Propanol is more soluble in water than propane due to its polarity in water.

From the second pair:

Propanone is an alkanone (ketone group) with three carbon chain directly bonded to an oxygen double bond. At the same time, 3-hexanone has six carbon chain ketone group with the oxygen double bond located at the third carbon chain ( a hydrophobic "water-fearing" compound). Thus, the shorter the carbon chain, the more polar the organic molecule is and the more it is likely going to dissolve in water. Therefore, Propanone is more soluble in water than 3-hexanone.

From the third pair: The shorter the carbon chain, the more soluble in water it will become.

Butanal is the fourth element on the alkanal family group while hexanal is the sixth compound in the alkanal family group. As such, butanal is more soluble in water than hexanal.

User Douglas Leeder
by
5.1k points