Chapter 13 · Solutions
13.2Solutions: Homogeneous Mixtures
8 min · two checks
Predict
Is a solution always a solid dissolved in water?
The idea
- Identify solute and solvent.
- Distinguish solutions from colloids and suspensions by behavior.
The solvent is the component present in the greater amount, or the one that sets the state. The solute is what got dissolved. Solutions can be gas–gas, gas–liquid, liquid–liquid, solid–liquid, or solid–solid. What they share is a single phase that does not settle. Sugar water does not need shaking to stay mixed. Sand in water does; that mixture is a suspension.
Colloids sit between solutions and suspensions. The particles are larger than molecules but too small to settle quickly, and they scatter light (the Tyndall effect). Milk and fog are colloids. True solutions do not settle and do not scatter a beam the way colloids do. For most calculations in this chapter the solute is dissolved as molecules or ions, and the mixture is a true solution.
Keep these
- Solvent: majority component. Solute: dissolved component.
- Solutions do not settle. Suspensions do.
- Colloids scatter light; true solutions do not.