Chemistry Lecture Review – States of Matter, Properties, Mixtures & Separation

Flashcards cover states of matter, solid properties, crystalline vs amorphous, salts, periodic table metal/non-metal behavior, ions, acids/bases, density, heat capacity, physical vs chemical changes, pure substances vs mixtures, homogeneous vs heterogeneous mixtures, and physical separation methods such as distillation, filtration, evaporation, chromatography, and centrifugation.

Which state of matter is relatively incompressible and has a definite volume and shape?

Solid

What distinguishes gases and liquids from solids in terms of volume?

Gases and liquids have an indefinite volume, while solids have a definite volume.

What type of solid lacks long-range order in its particle arrangement?

Amorphous solid

Table salt (NaCl) is an example of what broader class of compounds?

A salt – a compound formed between a metal cation and a non-metal anion.

On the periodic table, where are metals generally located relative to the staircase (jagged) line?

To the left of the staircase line.

When a metal atom reacts, does it typically lose or gain electrons, and what ion results?

It loses electrons to form a positive ion (cation).

Define a cation.

A positively charged ion formed when an atom loses one or more electrons.

Define an anion.

A negatively charged ion formed when an atom gains one or more electrons.

According to one common definition, an acid is any substance that produces which ion in water?

Hydrogen ion (H⁺).

According to a simple Arrhenius definition, a base produces which ion in water?

Hydroxide ion (OH⁻).

Write the basic heat-capacity (specific heat) equation introduced in class.

q = m c ΔT (heat = mass × specific heat × change in temperature).

In the equation q = m c ΔT, what does ΔT represent?

The change in temperature (final temperature minus initial temperature).

What physical property is calculated as mass divided by volume?

Density

Crushing a rock into powder is an example of which type of change—physical or chemical?

Physical change

Rusting of iron is classified as what type of change?

Chemical change (oxidation).

State two visual clues that a chemical reaction has taken place.

Formation of a new color, formation of a gas or solid (precipitate), temperature change, or light emission.

Substances on the left side of a chemical equation are called what?

Reactants

Substances on the right side of a chemical equation are called what?

Products

What are the two categories of pure substances?

Elements and compounds

How does a pure substance differ from a mixture with respect to composition?

A pure substance has constant composition throughout; a mixture can vary in composition.

What term describes a mixture that has the same composition throughout?

Homogeneous mixture

Give one everyday example of a heterogeneous mixture.

Ice cubes in lemonade (other examples acceptable: salad dressing, sandy water, etc.).

Can a pure compound be separated into its elements by physical means?

No; it requires a chemical change.

Name a physical technique used to separate a liquid mixture based on different boiling points.

Distillation

Which separation method uses a spinning force to separate components by mass or density?

Centrifugation

What laboratory technique separates components of a mixture as they move at different speeds along a surface with a mobile phase?

Chromatography

Filtration relies on what physical difference between mixture components?

Particle size/state of matter (solid retained, liquid passes through).

Evaporation separates a dissolved solid from a liquid by exploiting what physical process?

The liquid vaporizes (evaporates), leaving the solid behind.

Which of these properties—melting point, density, or combustibility—is chemical?

Combustibility

‘Conducting electricity’ is classified as what kind of property?

Physical property

What simple mnemonic mentioned in class helps remember the heat equation?

“MCAT” – q = m c ΔT

What is the unit ‘cc’ equivalent to in metric volume units?

One cubic centimeter (cc) equals one milliliter (mL).

Why does saltwater conduct electricity better than pure water?

Because dissolved ions (Na⁺, Cl⁻) in saltwater allow charge to flow, whereas pure water has very few ions.