heterogeneous mixture containing a liquid in which visible particles settle
The mixture described — a heterogeneous mixture containing a liquid in which visible particles settle out over time — is called a suspension.
What is a suspension?
A suspension is a type of heterogeneous mixture where solid particles are dispersed in a liquid (or sometimes a gas) but do not dissolve. The particles are large enough (usually over 1000 nm) to be visible to the naked eye or under a microscope, and they are not stable over time.
Because the particles are relatively heavy, they will eventually settle to the bottom of the container due to gravity when the mixture is left undisturbed. This settling is a key feature that distinguishes suspensions from other mixtures like solutions and colloids.
Examples of suspensions
Common everyday examples include:
- Muddy water (sand or silt in water)
- Flour or chalk powder stirred in water
- Paint before it’s stirred (some pigments can settle)
- Some medicines (like liquid antacids) that must be shaken before use
In these cases, the solid particles are visible and will sink to the bottom after a while, forming distinct layers.
How suspensions differ from colloids and solutions
- Solutions are homogeneous mixtures where the solute is completely dissolved in the solvent (e.g., salt in water); the particles are molecular or ionic in size and do not settle or scatter light strongly.
- Colloids are also heterogeneous but with much smaller particles (1–1000 nm) that do not settle under gravity in normal conditions (e.g., milk, fog, gelatin).
- Suspensions have large, visible particles that do settle and can often be separated by filtration.
Key properties of suspensions
A suspension is characterized by these properties:
- The mixture is heterogeneous : you can see different parts (solid and liquid).
- The particles are visible and large enough not to dissolve.
- They settle on standing due to gravity.
- They can be separated by filtration (solid is trapped, liquid passes through).
- They often scatter light (show the Tyndall effect), especially if the particles are still suspended.
So, in a multiple‑choice or fill‑in‑the‑blank chemistry question, the correct answer for “a heterogeneous mixture containing a liquid in which visible particles settle” is suspension.
Forum-style quick answer:
“It’s a suspension. Think of sand in water — you can see the sand, and it sinks to the bottom after a while. That’s the classic example they teach in school.”
Information gathered from public forums or data available on the internet and portrayed here.