Chapter 8: Solutions, Electrolytes, and Colligative Properties

Comprehensive vocabulary flashcards covering Chapter 8: mixtures, electrolytes, solubility principles, concentration units, dilutions, colligative properties, osmosis, and dialysis.

Heterogeneous Mixture

A mixture that does not have a uniform composition throughout the sample.

Homogeneous Mixture

A mixture that has a uniform composition throughout the sample.

Solution

A homogeneous mixture containing small particles ($< 1\,\text{nm}$) that cannot be separated by filtration and is transparent in liquid form.

Solute

The substance present in a lesser amount in a solution.

Solvent

The substance present in a larger amount in a solution.

Aqueous Solution

A solution where water is the solvent.

Colloid

A homogeneous mixture with larger particles ($1\,\text{nm} - 1\,\mu\text{m}$) that often appears opaque, does not settle out, and cannot be separated by common filtration techniques.

Suspension

A heterogeneous mixture containing large particles ($> 1\,\mu\text{m}$) suspended in a liquid that do not dissolve, settle over time, and can be separated by filtration or centrifugation.

Electrolyte

A substance that conducts an electric current when dissolved in water.

Nonelectrolyte

A substance that dissolves in water as uncharged molecules and does not conduct an electric current (e.g., $\text{CH}_3\text{CH}_2\text{OH}$, $\text{H}_2\text{O}_2$).

Strong Electrolyte

A solute that dissociates completely into ions in water to conduct an electric current (e.g., $\text{NaCl}$, $\text{KOH}$, $\text{HCl}$, $\text{KBr}$).

Weak Electrolyte

A solute that dissociates partially in water to form some ions while remaining mostly uncharged molecules, conducting an electric current (e.g., $\text{NH}_3$, $\text{CH}_3\text{CO}_2\text{H}$, $\text{HF}$).

Equivalent (Eq)

The number of moles of electrical charge contributed to a solution by one mole of an ion, equal to the numerical value of the ion's charge.

Solubility

The amount of solute that dissolves in a given amount of solvent, commonly reported in grams of solute per $100\,\text{mL}$ of solution ($\text{g}/100\,\text{mL}$).

Saturated Solution

A solution that contains the maximum number of grams of solute that can dissolve at a specific temperature.

Unsaturated Solution

A solution that contains less than the maximum number of grams of solute that can dissolve.

Supersaturated Solution

An unstable solution that contains more than the predicted maximum amount of solute at a given temperature, typically made by dissolving solute at high temperature and slowly cooling.

Exothermic Solvation

A dissolution process that releases heat because the solvation of particles releases more energy than is required to separate them.

Endothermic Solvation

A dissolution process that absorbs heat because the separation of particles requires more energy than is released during solvation.

Henry's Law

The principle stating that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid.

Weight/Volume Percent Concentration [(w/v)%]

A concentration unit defined as the number of grams of solute dissolved per $100\,\text{mL}$ of solution.

Volume/Volume Percent Concentration [(v/v)%]

A concentration unit defined as the volume of solute in milliliters dissolved per $100\,\text{mL}$ of solution.

Parts Per Million (ppm)

A concentration unit used for very small amounts of solute, representing parts of solute per $10^6$ parts of solution (e.g., $\text{g solute} / 10^6\,\text{mL solution}$).

Molarity (M)

The concentration of a solution expressed as the number of moles of solute dissolved per liter of solution ($\text{mol}/\text{L}$).

Dilution

The addition of solvent to decrease the concentration of solute, increasing the total volume while the amount of solute remains constant ($C_1V_1 = C_2V_2$ or $M_1V_1 = M_2V_2$).

Colligative Properties

Physical properties of a solution that depend solely on the concentration of solute particles present, rather than their chemical identity.

Volatile Solute

A solute that readily escapes into the vapor phase, exhibiting a significant vapor pressure.

Nonvolatile Solute

A solute that does not readily escape into the vapor phase and possesses negligible vapor pressure at a given temperature.

Boiling Point Elevation

A colligative property in which the boiling point of a solution containing a nonvolatile solute is higher than that of the pure solvent alone.

Freezing Point Depression

A colligative property in which the freezing point of a solution containing a nonvolatile solute is lower than that of the pure solvent alone.

Semipermeable Membrane

A membrane that permits water and small molecules to pass through while blocking the passage of ions and large molecules.

Osmosis

The flow of solvent (typically water) through a semipermeable membrane from a solution of lower solute concentration to one of higher solute concentration.

Osmotic Pressure

The pressure that prevents the net flow of additional solvent across a semipermeable membrane into a solution.

Isotonic Solution

A solution that has the same osmotic pressure as body fluids, such as a $0.92\%\,\text{(w/v) NaCl}$ solution or a $5.0\%\,\text{(w/v) glucose}$ solution.

Hypotonic Solution

A solution that has a lower osmotic pressure and lower solute particle concentration than body fluids, causing water to diffuse into cells.

Hemolysis

The swelling and bursting of red blood cells caused by water rushing inward when placed in a hypotonic solution.

Hypertonic Solution

A solution that has a higher osmotic pressure and higher solute particle concentration than body fluids, causing water to diffuse out of cells.

Crenation

The shrinking and shriveling of red blood cells caused by net water loss when exposed to a hypertonic solution.

Dialysis

The biological filtration process in the kidneys where water, small molecules, and ions cross a semipermeable membrane to eliminate wastes like urea while retaining large biological molecules.

Hemodialysis

An external medical procedure used to filter waste products from the blood when an individual's kidneys fail.