Key Takeaways
- Yes - acetone and water are completely miscible: they mix in all proportions with no solubility limit (i.e. no maximum g/L value applies, since acetone dissolves in water at any ratio up to pure acetone).
- The polar carbonyl group of acetone accepts hydrogen bonds from water molecules.
- Acetone itself cannot form hydrogen bonds with other acetone molecules; its intermolecular forces are dispersion forces.
- This hydrogen-bond acceptance is why acetone behaves like a polar solvent and mixes with water, unlike non-polar solvents such as hexane.
1. The Short Answer
Yes. Acetone (CAS 67-64-1) dissolves completely in water - the two liquids are miscible in all proportions, so there is no upper solubility limit.
2. Why Acetone And Water Mix
Acetone molecules have a polar carbonyl group (C=O) that allows them to accept hydrogen bonds from other compounds, including water. Acetone itself has no polar O-H or N-H bonds, so acetone molecules cannot form hydrogen bonds with each other; the intermolecular forces between acetone molecules are dispersion forces. Water, on the other hand, has two polar O-H bonds: the slightly positive hydrogen atoms attract slightly negative oxygen atoms of neighbouring water molecules, forming hydrogen bonds. When acetone is added to water, the polar carbonyl group accepts hydrogen bonds from water, so the acetone molecules are surrounded and stabilised by water molecules - the mixture is homogeneous at any ratio.
3. The Bigger Picture: Polarity And "Like Dissolves Like"
The rule of thumb "like dissolves like" works here: both water and acetone are polar, so they mix freely. Acetone's hydrogen-bond-accepting carbonyl makes it an effective polar solvent for many polar and hydrogen-bonding solutes, and the ability to dilute acetone with water is useful in cleaning and formulation work. By contrast, non-polar solvents such as hexane do not mix with water, because they cannot form the hydrogen-bond network that water requires.
Frequently Asked Questions
What is the solubility of acetone in water?
Acetone is infinitely soluble in water - meaning there's no fixed solubility value in g/L, since the two are miscible in all proportions, from a trace of acetone in water up to pure acetone. Unlike substances with a solubility limit (e.g. "36 g per 100 mL"), acetone-water mixtures stay a single homogeneous phase no matter the ratio.
Can acetone dissolve in water?
Yes. Acetone dissolves in water completely, at any ratio, because its polar carbonyl group (C=O) forms hydrogen bonds with water molecules, letting acetone mix into water's hydrogen-bond network instead of separating out.
Q1. Is there a solubility limit for acetone in water?
No - acetone and water are completely miscible in all proportions.
Q2. Why can acetone accept hydrogen bonds but not donate them?
Its polar carbonyl oxygen is a strong hydrogen-bond acceptor, but acetone has no O-H or N-H group to donate a hydrogen bond.
Q3. Does acetone form hydrogen bonds with itself?
No - acetone molecules interact through dispersion forces, which is why pure acetone boils at a relatively low temperature.
Q4. Can I dilute acetone with water for cleaning?
Yes, water-acetone mixtures are used in cleaning and formulation; keep flammability and ventilation in mind.