Is everything slightly soluble?

Is Everything Slightly Soluble?

It’s a common saying in chemistry: “Everything dissolves a little.” But is that really true? The answer isn’t quite so absolute. While many substances can dissolve to some degree, the reality is more nuanced—solubility spans a vast spectrum, from complete mixing to virtually no interaction at all.

Take ethanol and water, for example. These two liquids are infinitely soluble in each other—or, as chemists say, they’re miscible. Mix them in any proportion, and they’ll form a uniform solution. On the opposite end, substances like titanium dioxide (a common white pigment) are essentially insoluble in water. Even under the most sensitive detection methods, the amount that dissolves is so minuscule it’s practically negligible.

So, can we say everything is slightly soluble? Technically, even the most insoluble-looking substances might release a few molecules into solution—perhaps just a few parts per billion. But from a practical standpoint, calling something “insoluble” makes sense when its dissolution has no measurable effect. In engineering, medicine, or environmental science, these distinctions matter.

Consider table salt: highly soluble in water, which is why it disappears so easily in soup. Now compare that to sand, mostly made of silica. Pour water over it, and it stays put. There might be a few stray molecules entering the liquid, but not enough to affect anything we can observe or measure in daily life.

In the end, solubility isn’t a yes-or-no question—it’s a matter of degree. Some things mix completely, others barely budge, and most fall somewhere in between. The key is recognizing when that “slight” solubility actually matters—and when it’s safe to ignore.