Chemistry: Volume, Density, Matter Properties, and Gas Tests Review

Volume

A measure of how much space an object takes up (cm³, mL, m³)

Calculation (liquid)

√=m

Calculation (prism)

V = lhw

How to determine the volume of an irregularly shaped object?

We can use a method called 'the displacement of water'. Record volume of water in a graduated cylinder, lower object into cylinder, record new volume, subtract values to get volume.

For Large Irregular Objects

Fill an overflow can with water, wait until excess is poured out, place empty cylinder under the spout of the overflow can, lower object into overflow can and collect water that pours out, then measure volume of water.

Density

A measure of how tightly packed the particles are in an object (g/mL)

How to find density?

D = m/V

What does the density of an object tell you?

It tells us how closely packed the particles of a material are.

Mass

A measure of all the 'stuff' contained in an object (protons, electrons, neutrons) measured in g (small) or kg (large).

Matter

Anything that has mass and takes up space.

Physical Property

A property of a substance that can be determined without changing the composition of that substance, e.g. lustre, ductility.

Qualitative physical properties

Are not measured and include hardness, malleability, and electrical conductivity.

Quantitative physical properties

Are measured and include temperature, height, and mass.

Physical change

A change in which the composition of the substance remains unaltered and no new substances are produced. Examples: melting ice, dissolving sugar.

Chemical Property

When the composition of the substance is changed and one or more new substances are produced. Example: fireworks.

Chemical change

A change in the starting substance or substances and the production of one or more new substances.

Homogeneous

Looks the same. E.g. saltwater, mouthwash.

Heterogeneous

Doesn't look the same. Can also be called Mechanical Mixtures e.g., pizza, solid waste dump.

Particle Theory of Matter

A theory that describes the composition and behaviour of matter.

Pure Substance

A substance that is made up of only one type of particle.

Mixture

A substance that is made up of at least two different types of particles.

Solution

A uniform mixture of two or more substances.

Element

A pure substance that cannot be broken down into a simpler chemical substance by any physical or chemical means.

Compound

A pure substance composed of two or more different elements that are chemically joined.

How to Test the Presence of Hydrogen

Insert a blazing wood into the gas. If there is a popping sound, it is likely hydrogen.

How to Test the Presence of Oxygen

Insert a glowing splint into the gas. If the splint glows brightly or bursts into flame, it is likely oxygen.

How to Test the Presence of Carbon Dioxide

Mix it with clear lime water solution. If it turns cloudy, then it is…

Gases produced by the electrolysis of water

Hydrogen gas and oxygen gas are produced. The relative amount comes from H₂O, 2 hydrogen atoms for every 1 oxygen atom.