Elements, Compounds and Mixtures

Flashcards about elements, compounds, mixtures, acids, and bases.

Elements and compounds with fixed compositions are called?

Substances.

What are the two major categories of matter?

Mixtures and substances.

How is a mixture different from a compound?

Substances in a compound are chemically combined. The substances in a mixture are not.

What is true about mixtures and compounds?

Mixtures are formed when substances physically combine while compounds are formed when they are chemically combined. In mixtures the substances keep their properties, but in compounds the substances combined can lose their properties and become a new substance. Compounds require a chemical reaction to separate their parts, but a mixture can be physically separated.

Why is oxygen a pure substance and air a mixture?

Oxygen contains only one substance, but air contains several substances.

What is a solution?

A solution is a homogeneous mixture with tiny particles.

Is salad dressing a heterogeneous mixture?

True

What is a solution with a higher solute concentration than possible at a given temperature/pressure called?

A supersaturate

Is lemonade without pulp a heterogeneous mixture?

False

What is a combination of two or more substances not chemically combined?

Mixture

Which substance from the provided list is the most alkaline: Blood (pH 7.3), Orange Juice (pH 4.0), Ammonia (pH 11.0), Milk (pH 6.5)?

Ammonia

List the substances from least to most acidic: Blood (pH 7.3), Orange Juice (pH 4.0), Ammonia (pH 11.0), Milk (pH 6.5).

ammonia, blood, milk, orange juice

What is the major difference between concentration and solubility?

Concentration is measured in grams of solute per 100 mL of solution and solubility is measured in grams of solute per 100 mL of solvent.

Does a concentrated solution contain less solute than a dilute solution?

False

In a sugar and water mixture what is the sugar?

Solute

The strength of an acid depends on the concentration of what ions?

Hydronium ions

If a substance changes color and produces bubbles when mixed, what kind of change likely occurred?

A chemical change took place.

Which chemical can be found in indigestion tablets?

Calcium carbonate

What is the universal solvent?

Water

A solution at pH 11.5 is…?

Basic

Give examples of acids and bases.

Acids: vinegar. Bases: soap, blood, alkaline batteries, baking soda, ammonia.

If you dissolve 20 grams of salt in 100 milliliters of water, what is the concentration of the salt solution in grams per milliliter (g/mL)?

0.2 g/mL