Basics of Mixtures and Solutions
A combination of two or more substances that are physically mixed but not chemically combined.
What is a mixture?
: A mixture that is not uniform throughout and has visibly distinct components or phases, like sand in water.
What is a heterogeneous mixture?
The most common unit of concentration in chemistry, defined as moles of solute per liter of solution.
What is molarity (M)?
The general process by which solute particles are surrounded by solvent particles when a solution forms.
What is solvation?
Properties of solutions that depend only on the number of solute particles present, not on the identity of those particles.
What are colligative properties?
A homogeneous mixture where one substance is uniformly dissolved in another, appearing as a single phase.
What is a solution?
A heterogeneous mixture with very large particles that will eventually settle out if left undisturbed, such as muddy water.
What is a suspension?
The concentration unit defined as moles of solute per kilogram of solvent.
What is molality (m)?
The specific term for the solvation process when water is the solvent.
What is hydration?
An example of a colligative property that causes a solution to freeze at a lower temperature than the pure solvent.
What is freezing point depression? (Also boiling point elevation, vapor pressure lowering, osmotic pressure)
In a solution, this is the substance that gets dissolved, typically present in the smaller amount.
What is the solute?
A heterogeneous mixture with intermediate-sized particles that remain dispersed and do not settle out, like milk or fog.
What is a colloid?
If you dissolve 0.75 moles of potassium chloride (KCl) in enough water to make 1.5 L of solution, this is its molarity.
What is 0.50 M? (Calculation: 0.75 mol / 1.5 L = 0.50 M)
One of the three factors that can increase the rate at which a solid solute dissolves in a liquid solvent (besides the nature of the substances).
What is increasing temperature, increasing surface area, or agitation (stirring)? (Any one is acceptable)
A substance that dissolves in water to produce ions, allowing the resulting solution to conduct an electric current.
What is an electrolyte?
In a solution, this is the substance that does the dissolving, typically present in the larger amount.
What is the solvent?
The phenomenon where a beam of light becomes visible as it passes through a colloid due to the scattering of light by the dispersed particles.
What is the Tyndall effect?
The formula used to calculate the new concentration or volume when a solution is diluted.
What is M1V1 = M2V2?
A solution that contains the maximum amount of solute that can be dissolved at a specific temperature and pressure.
What is a saturated solution?
An example of a strong electrolyte that completely dissociates into ions when dissolved in water.
What is sodium chloride (NaCl) or hydrochloric acid (HCl) or potassium hydroxide (KOH)? (Any strong acid, strong base, or soluble ionic compound)
A common example of a solution formed when sugar is completely dissolved in water.
What is sugar water?
The random, erratic, zigzag movement of colloidal particles caused by their collisions with the molecules of the dispersion medium.
What is Brownian motion?
If you dilute 50.0 mL of a 3.0 M stock solution to a final volume of 300.0 mL, the new concentration is 0.50 M.
What is 0.50 M? (Calculation: (3.0 M * 50.0 mL) / 300.0 mL = 0.50 M)
A solution that contains more solute than a saturated solution at the same temperature, often prepared by cooling a saturated solution slowly.
What is a supersaturated solution?
To find the number of moles of solute in 500 mL of a 0.25 M solution, you would calculate 0.125 moles.
What is 0.125 moles? (Calculation: 0.25 mol/L * 0.500 L = 0.125 mol)