Solutions, Acids, and Bases
All matters are composed of atoms that have mass and occupy space.
Matter can be classified into pure substances (homogeneous matter) and mixtures
(heterogeneous matter). Homogeneous matter (pure substances) has a uniform composition,
while heterogeneous matter (mixtures) does not.
Pure substances are further divided into elements (e.g., H₂, Cu) and compounds (e.g., H₂O,
NaCl(s)), typically consisting of only one type of atom. Mixtures are categorized further, which
we’ll explore next!
Mixtures
A homogeneous mixture has a uniform structure, while a heterogeneous mixture is unevenly
distributed and lacks structure.
For example, mixing pepper and salt creates a heterogeneous mixture with no defined
composition. Vinegar is a homogeneous mixture, not a pure substance, because water (the solute)
is dissolved in acetic acid (the solvent). Homogeneous mixtures, also known as solutions, are
usually liquids (like vinegar) but can also include gases.
Phases are samples with a uniform composition. A homogeneous mixture has one phase, while a
heterogeneous mixture has two or more phases. For instance, mixing oil and vinegar creates
layers, making it a heterogeneous mixture.
Homogeneous mixtures break down into solutions, which have the smallest particles. Solids are
alloys, liquids are aqueous solutions (e.g., NaCl(aq)), and gases include air, where gases like O₂
are dissolved in nitrogen. Alloys are mixtures of two or more elements, with at least one being a
metal. Solution particles are too small to be separated by filter paper.
Colloids are heterogeneous mixtures with particles larger than those in solutions but smaller than
those in suspensions. Colloids appear milky or misty and exhibit the Tyndall Effect, where light
is scattered by the particles. For example, fog is a colloid. Colloid particles do not settle and
remain suspended indefinitely, like in milk. This distinguishes colloids from suspensions.
Suspensions are heterogeneous mixtures with the largest particles. These particles remain
suspended briefly before settling due to their size.
Solubility
Soluble: Solute dissolves in solvent (aq)
Insoluble: Solute does not dissolve in solvent (s)
Solubility: Degree to which a solute dissolves in a solvent
All matters are composed of atoms that have mass and occupy space.
Matter can be classified into pure substances (homogeneous matter) and mixtures
(heterogeneous matter). Homogeneous matter (pure substances) has a uniform composition,
while heterogeneous matter (mixtures) does not.
Pure substances are further divided into elements (e.g., H₂, Cu) and compounds (e.g., H₂O,
NaCl(s)), typically consisting of only one type of atom. Mixtures are categorized further, which
we’ll explore next!
Mixtures
A homogeneous mixture has a uniform structure, while a heterogeneous mixture is unevenly
distributed and lacks structure.
For example, mixing pepper and salt creates a heterogeneous mixture with no defined
composition. Vinegar is a homogeneous mixture, not a pure substance, because water (the solute)
is dissolved in acetic acid (the solvent). Homogeneous mixtures, also known as solutions, are
usually liquids (like vinegar) but can also include gases.
Phases are samples with a uniform composition. A homogeneous mixture has one phase, while a
heterogeneous mixture has two or more phases. For instance, mixing oil and vinegar creates
layers, making it a heterogeneous mixture.
Homogeneous mixtures break down into solutions, which have the smallest particles. Solids are
alloys, liquids are aqueous solutions (e.g., NaCl(aq)), and gases include air, where gases like O₂
are dissolved in nitrogen. Alloys are mixtures of two or more elements, with at least one being a
metal. Solution particles are too small to be separated by filter paper.
Colloids are heterogeneous mixtures with particles larger than those in solutions but smaller than
those in suspensions. Colloids appear milky or misty and exhibit the Tyndall Effect, where light
is scattered by the particles. For example, fog is a colloid. Colloid particles do not settle and
remain suspended indefinitely, like in milk. This distinguishes colloids from suspensions.
Suspensions are heterogeneous mixtures with the largest particles. These particles remain
suspended briefly before settling due to their size.
Solubility
Soluble: Solute dissolves in solvent (aq)
Insoluble: Solute does not dissolve in solvent (s)
Solubility: Degree to which a solute dissolves in a solvent
