flvs unit 8 solutions study guide

8.01:

• water is polar

  • has a -oxygen end and a +hydrogen end

  • attracts other molecules. "sticky"

• cohesion- when water molecules stick together

  • hydrogen bonding happens between water molecules

• lemonade -water = solvent -powder = solute

• stronger attraction= easier to dissolve.

8.02: molarity, dilutions

concentration- ratio of solvent to solute.

can be measured in:

• molarity- 3 of solute moles in 1L of solution

  • to find molarity, you need the # moles in the solute and the amount of solvent.

  • molarity= moles of solute/ L of solution

• percent by mass- #g of solute in 100g of solution

  • expressed as a %

8.04: acids/ bases

acid- sour, corrosive, H+ aka hydrogen, donate a hydrogen ion. hydrochloric, nitric, sulfuric acids

base- bitter, slippery, OH- aka hydroxide, receive a hydrogen ion. sodium, potassium, lithium hydroxide

• svante arrhenius's definitions:

  • acid- contains hydrogen, increases hydrogen ions when the acid is dissolved in a solution.

  • base- contains hydroxide, increases hydroxide ions when the base is dissolved in a solution

• when an acid and a base come together, they neutralize.

  • produces water and a salt/ ionic compound

• ph measures acidity/ alkalinity of a solution.

  • 1= acid (lemon juice), 7= neutral (water), 14= base (bleach)

8.05: acid and base calculations

• self-ionization- lets water act as a weak electrolyte and conducts electricity

• amphoteric substance- water can be acid or base, depending on what’s added to it.

  • an acid-acting water molecule donates a hydrogen ion to a base-acting water molecule.

    • this reaction forms hydroxide and hydronium ions, which react to re-form water molecules.

      • ionization constant

• the product of hydronium and hydroxide molarities is always =1x10^-14 M

• acids increase concentration of hydronium ions by donating hydrogen ions

• base decrease concentration of hydronium ions by accepting hydrogen ions

• basic- concentration of hydroxide ions greater than concentration of hydronium.

  • adding a base (ammonia) to water increases hydroxide concentration

• neutral- when concentrations of hydronium and hydroxide are equal

• acidic- concentration of hydronium ions greater than concentration of hydroxide.

  • adding an acid (hydrochloric acid) to water increases hydronium concentration