Mixtures, Solutions & Separation Techniques

Flashcards reviewing types of mixtures, solubility, solution properties, concentration, measurement, and common separation methods.

What two components combine to form a solution?

A solute fully dissolved in a solvent.

Define a solution.

A homogeneous mixture in which the solute is completely dissolved and particles are invisible to the naked eye.

Give one everyday example of a solution.

Salt dissolved in water (saltwater) or sugar dissolved in water (sugar water).

Define a suspension.

A heterogeneous mixture where particles are mixed but large enough to settle out or be seen, e.g., flour in water.

Give one everyday example of a suspension.

Mud (dirt mixed with water) or flour mixed with water.

Define a colloid.

A heterogeneous mixture with particles too light to settle but not fully dissolved, remaining dispersed throughout, e.g., milk or toothpaste.

How does a light beam behave in a solution?

The light beam is not visible when it passes through a true solution.

How does a light beam behave in a suspension?

The light beam is visible because larger particles scatter light.

How does a light beam behave in a colloid?

The light beam is visible due to the Tyndall effect—scattering by intermediate-sized particles.

What does it mean when a substance is soluble?

It is able to dissolve in a given solvent.

What term describes a substance that cannot dissolve?

Insoluble.

Define homogeneous mixture.

A mixture whose components are uniformly distributed so it looks the same throughout.

Define heterogeneous mixture.

A mixture whose components are not evenly distributed and can be easily distinguished.

What is meant by a diluted solution?

A weak solution containing relatively little solute compared with solvent.

What is meant by a concentrated solution?

A strong solution containing a large amount of solute relative to the solvent.

Define a pure substance.

Matter made up of only one kind of particle, such as pure water, gold, or salt.

Which separation method is best for separating a suspension’s solid from its liquid?

Filtration.

Which technique is used to recover a dissolved solid from its solution?

Evaporation (heating until the solvent evaporates, leaving the solute behind).

Which technique separates mixtures of metals and non-metals?

Magnetism (using a magnet to attract metallic particles).

Which separation technique is ideal for separating colours in inks or dyes?

Chromatography.

Which device separates particles of different sizes by allowing smaller pieces to fall through holes?

Sieving.

What is decanting?

Pouring off the top liquid after a suspension has settled, leaving the solid behind.

Which process obtains pure water from a solution by evaporation followed by condensation?

Distillation.

At what part of the meniscus should liquid volume be read in a graduated cylinder?

At the bottom of the meniscus (the lowest point of the curved surface).