Chemistry Mixtures and Solutions Quiz

Study Notes

Mixtures are combinations of substances that are not chemically bonded.
Heterogeneous mixtures have non-uniform composition, meaning the macroscopic properties vary throughout the mixture, like soil.
Homogeneous mixtures have uniform composition and macroscopic properties don't vary, like salt water.

Solutions are homogeneous mixtures where the solute is uniformly distributed within the solvent.
The solute is the substance that is dissolved, while the solvent is the substance that does the dissolving.
Solutions can be formed from solids, liquids, or gases.

Solid Solutions: Alloys like steel (solute: carbon, solvent: iron) and brass (solute: zinc, solvent: copper) are formed by mixing molten metals and allowing them to cool.
Liquid Solutions: Common examples include saltwater (solute: salt, solvent: water), sugar water (solute: sugar, solvent: water), and lemonade (solutes: sugar and lemon juice, solvent: water).
Gas Solutions: Air is a gas solution, and carbonated water is another example where dissolved carbon dioxide acts as the solute and water as the solvent.

Solvation is the process where a solvent dissolves a solute, forming a solution. Solvent molecules surround solute particles, leading to solvation.
When the solvent is water, solvation is referred to as hydration, meaning the solute particles are surrounded by water molecules

Concentration measures the amount of solute dissolved in a given amount of solvent.
Molarity (M) is the most common measure of concentration, defined as moles of solute per liter of solution (M = moles of solute/liters of solution), with units of mol/L.
For example, a solution with 24 moles of HCl in 2 liters of water has a molarity of 12 M (24/2 = 12).

Mass percent: Calculated as (mass of solute / mass of solution) x 100, remembering to add the mass of solute and solvent to get the mass of the solution.
Molality (m): Defined as moles of solute per kilogram of solvent (m = moles of solute / kilograms of solvent).