Chemistry: Matter and Mixtures Concepts

These flashcards cover essential concepts related to matter, mixtures, and properties in chemistry, based on the provided lecture notes.

What is matter?

Matter is anything that has mass and takes up space.

What is a pure substance?

A substance with fixed composition; examples: gold, water.

Define an element and give two examples.

An element is a substance made of one kind of atom; examples include oxygen and copper.

Define a compound.

A compound is a substance formed from two or more elements chemically combined in a fixed ratio.

What is a mixture? How can mixtures be separated?

A mixture is a physical blend of substances; it can be separated by filtering, using a magnet, evaporation, distillation, or tweezers.

What is the difference between heterogeneous and homogeneous mixtures?

Heterogeneous mixtures have uneven, visible parts; homogeneous mixtures are evenly mixed with no visible parts.

Define suspension.

A suspension is a heterogeneous mixture with large particles that settle over time.

What is a colloid?

A colloid is a mixture where particles never settle; the Tyndall Effect is the scattering of light by colloid particles.

What is a solution? Identify solute and solvent.

A solution is a homogeneous mixture; the solute dissolves while the solvent does the dissolving.

What is a physical property?

A physical property is a characteristic observed without changing the substance, such as color, density, or boiling point.

What is a chemical property?

A chemical property is a characteristic observed during a chemical reaction, like flammability or reactivity.

How can you separate a mixture of sand, salt, and iron filings?

Use a magnet to remove iron, add water to dissolve the salt, filter the sand from the saltwater, and evaporate the water from the salt.

How can you find the volume of an irregular solid?

Record the initial water level, place the object in water, record the new water level, and subtract to find the volume.

Why is dissolving sugar in water a physical change?

The sugar can be separated from the water.

What are signs of a chemical change?

Signs include color change, temperature change, gas bubbles produced, precipitate formed, and odor change.

Why does a block of wood float on the surface of water?

It has a lower density than water, allowing it to float.

Which of the following is not a pure substance: A. Gold B. Water C. Trail Mix D. Carbon Dioxide?

C. Trail Mix is not a pure substance.

Which type of mixture has particles large enough to settle out over time?

Suspension.

Which mixture allows light to scatter?

Colloid.

What is the best example of a solution?

Salt Water.

A sample has a mass of 45 g and a volume of 5 cm³. What is its density?

Density = 9 g/cm³.

A block has a density of 0.75 g/cm³ and a mass of 18 g. What is its volume?

Volume is 24 cm³.

A liquid has a density of 1.05 g/mL. If you have 250 mL, what is the mass?

Mass = 262.5 g.

Object A sinks in water while Object B floats. What can you say about their densities?

Object A has a density greater than 1; Object B has a density less than 1.

Classify CO2 gas, vinegar, trail mix, and aluminum.

CO2 gas: Compound; Vinegar: Solution; Trail Mix: Heterogeneous Mixture; Aluminum: Element.