Which item below is NOT an example of how the general rule for dissolving works?

A.

Oil and water do not mix.

B.

Oil and water mix.

C.

Water and methanol mix.

D.

Methanol and oil do not mix.

E.

Oil and grease mix.

Answer: B. Oil and water mix.

Explanation:

The solubility of substances is governed by: Like dissolves like, which states that polar compounds are soluble in polar solvents and non polar compounds are soluble in non polar solvents.

Oils and grease are non polar in nature due to less difference between the electronegativities of carbon and hydrogen and thus are soluble in non polar solvents only.

Water and methanol being polar solvents get dissolved in each other.

Thus oil and water do not mix as water is polar and oil is non polar.

B.

Oil and water mix

Explanation:

Everyone knows oil and water don't mix

It had to be A or B, because they oppose each other.