Pure Substances and Mixtures

Compound

A molecule is the smallest unit of a compound. Examples of pure substances that are compounds are alcohol, water, baking soda, and glucose.

Describe the process of distillation. What substances can it separate?

Distillation is a laboratory technique for separating a liquid from a solution using heat. It can seperate salt from water

What substances are best separated by evaporation? Describe.

Evaporation and distillation are processes that can separate solids, liquids, and gases from a solution using heat. However, evaporation is good for separating a soluble solid from a liquid.

Describe filtration and the physical properties of the substances that can be separated by this means

Making coffee: The liquid water and the dissolved coffee pass through the filter, while the solid coffee grounds that did not dissolve in the water remain behind on the filter paper. insoluble solids remain behind on the filter paper as the liquid passes through it.

What physical property is used to separate substances in a centrifuge? How is it done?

Salad dressings like vinaigrettes are a mix of oil and vinegar, two liquids that don't mix normally. Since the densities of these liquids are different, eventually one liquid settles to the bottom and the other rises to the top. centrifuge can be used to speed up the process. A centrifuge spins at high speeds until the heavier components (solids or liquids) sink to the bottom and the lighter components (liquids or gases) float to the top.

Define solute and solvent.

Solute- dissolves in solvent, what is being dissolved Solvent- what is dissolving solute

How can a mixture be separated into pure substances?

by a physical process.

What physical properties can be used to separate heterogeneous mixtures?

can be separated based on physical properties such as size, color, or magnetism.

Properties

characteristics used to describe an object

Colloids

generally considered heterogenous because some areas of these mixtures have a larger number of insoluble particles in suspension.

Heterogeneous mixture

heterogeneous mixture is a mixture that has its different components mixed unevenly within the substance. salad dressing, rocks, cereal, and sand.

Homogeneous mixture

homogeneous mixture is a mixture that has its different components mixed evenly within the substance. air, perfume, bleach, orange juice (without pulp), and steel.

Solutions

homogeneous mixtures in which the solute is dissolved and distributed evenly within the solvent.

Emulsions

homogeneous mixtures of two or more liquids that are normally not mixable. They need a third substance to help them mix together.

What physical properties can be used to separate homogeneous mixtures?

require a little more work to separate their components. Heat, pressure, and differences in density

How can a compound be separated into individual elements?

separated only by a chemical process.

Pure substance

single element or type of compound. For example, gold is a pure substance made from a single element: gold.

Mixture

solids, liquids, or gases mix with one another

Element

substance that cannot be broken down into simpler substances elements on the periodic table of elements are examples of pure substances.

Composition

the chemical makeup of a rock; describes either the minerals or other materials in the rock

What types of substances can be separated using a magnet?

you wanted to separate a mix of salt and iron. Much like a metal detector at the beach, you could use a magnet to attract the iron, causing it to move away from the salt molecules.