Which of the following is more soluble in water, methanol or CBr2H2(l).

Question

How do I figure this out? Is there an equation or is this just basic chemistry knowledge?

Answer 1

There is no equation, but one can generally determine solubility/miscibility or rank in solubility/miscibility by looking at the structure of the compound.

Methanol = CH3OH. Note the -OH group. This not only makes this molecule polar, but also allows for hydrogen bonding with water (H-OH). This will certainly be soluble/miscible in water.

CBr2H2 = dibromomethane. I can't easily draw the structure here, but do look it up. You will see that it is asymmetrical and has a tetrahedral geometry, so it is polar, but does NOT exhibit hydrogen bonding. Also, the polarity is less than that for methanol. So, it will be soluble/miscible in water, but much less so than methanol.

Answer 2

Janel,

The correct answer is methanol because of the interaction of the its hydroxy group and hydrogens with the water molecule that separate the methanol molecules, there by dissolving the methanol. This same process occurs with the other compound but not as rapid as methanol. And yes, n general chemistry, this should be covered.