The Amazing World of Solutes, Solvents, and Solutions: questions with answers

A solution that can still dissolve more solute at a given temperature is unsaturated. When the solute stops dissolving and begins to settle, no more will dissolve at that temperature, and the solution is saturated.

The sand grains remain a separate solid phase and settle after stirring. In this sand-water case, settling shows a suspension rather than a solution.

Solute and solvent are the parts of a solution, and a solution is a uniform mixture. Sand does not dissolve in water: it separates out on standing, making a non-uniform mixture. So neither name applies here.

The amount rule applies when both components are liquids. When a solid dissolves in a liquid, the states decide instead: the solid is the solute and the liquid is the solvent, however much of each there is.

Concentrated compares one solution with another; saturated names the point at which no more solute will dissolve at a given temperature. A concentrated solution may still be well short of that point.

A solubility value describes the maximum dissolved amount for a specified solvent quantity and temperature. Temperature can change that maximum, so the label is incomplete.

Many fish obtain oxygen dissolved in water through their gills. A small dissolved amount can therefore be important for their survival.

For most solids, solubility increases as the temperature rises. Water at 70 degrees Celsius therefore dissolves more baking soda than water at 20 degrees Celsius does.

The stone pushes aside its own volume of water, so the water rises by exactly that amount, whatever the stone weighs. Taking the first reading from the second gives 71 mL - 60 mL, and a volume of liquid in millilitres is written in cubic centimetres for a solid.

Pressing tare with only the container on the pan sets the display to zero, so the container no longer counts. Anything placed on it afterwards is what the balance then reads.

The 50 mL cylinder cannot hold 70 mL in one filling. Among the cylinders that can, the 100 mL cylinder has the smallest divisions.

For the concave water surface shown, read the lowest point of the meniscus. Keep your eye at that level to avoid a viewing-angle error.

Relative density is the density of a substance divided by the density of water at that temperature. Both are densities in the same unit, so the unit cancels and what is left is a plain number.

Mass is the quantity of matter in an object; volume is the space it occupies; density is the mass present in one unit of volume. The space occupied is the volume, and it is a different quantity from the mass.

In this setup, the rise shows expansion of the liquid. No liquid was added and none overflowed. The same sample takes up more space.