Untitled Quiz

Mixtures

• A homogeneous mixture has uniform composition, like salt water or coffee.
• A heterogeneous mixture has non-uniform composition with different properties, like soil or cookies.

Solubility & Solutions

• A solvent dissolves a solute to form a solution.
• Solutes are dissolved in a solvent, forming a homogeneous mixture.
• The solubility of a substance is the amount that can dissolve in a solvent at a particular temperature.
• Most solids dissolve better in hotter solvents.
• Polar solutes dissolve better in polar solvents, and nonpolar solutes dissolve in nonpolar solvents.

"Like Dissolves Like"

• Polar compounds dissolve polar compounds (e.g., water and sugar)
• Nonpolar compounds dissolve nonpolar compounds (e.g., oil and grease)
• Polar and nonpolar compounds do not dissolve in each other (e.g., water and oil).

Polar vs. Nonpolar Molecules

• Polar molecules have uneven electron sharing, creating a positive and negative "pole" (like a battery).
• Polar molecules are hydrophilic (water-loving)
• Nonpolar molecules have even electron sharing, resulting in no distinct positive or negative areas.
• Nonpolar molecules are hydrophobic (water-fearing).

Water - The Universal Solvent

• Water is a polar molecule due to oxygen's higher electronegativity.
• The oxygen end has a partial negative charge, and the hydrogen end has a partial positive charge.

Hydrophilic vs. Hydrophobic

• Charged molecules (ionic and polar) are hydrophilic, attracted to water, and water-soluble.
• Uncharged molecules (nonpolar) are hydrophobic, repelled by water, and not water-soluble.