Water and pH

Hydrophobic

Molecules that hate water

Hydrophilic

Molecules that love water

Evaporation

The transition from a liquid state to a gaseous state occuring at the surface of a liquid

Specific Heat

The amount of heat needed to raise 1g of water 1^oC. Water will boil at 100^oC

Cohesion

The result of hydrogen bonds between water molecules. Water sticking to itself. This allows for capillarity

Surface Tension

Occurs when water molecules at the surface from stronger hydrogen bonds with the water molecules on either side. Like a bug standing on water

Adhesion

When hydrogen bonds form between water molecules and other polar molecules, or water sticking to other molecules.

Formula Weight (FW)

The sum of atomic weights (amu — atomic mass unit) of each atom in the chemical formula

Molecular Weight (MW)

The weight when the chemical formula is also its molecular formula

Solutions

Homogenous mixtures of two ro more substances

Solute

The substance dissolved by the solvent, and is present in the smallest amount.

Solvent

Used to dissolve solute. Present in the greater quantities.

Hydrogen Atom

Has one proton and one electron

Hydrogen Ion

Has one positively charged proton and lost its electron

H₂O —> OH^- + H⁺

Equation for the dissociation of water

Dissociates

When the water molecule falls apart due to one of the polar covalent bonds of the water pulling the electrons so far towards the oxygen

Hydronium Ion

H₃O⁺, due to an H⁺ getting quickly picked up by a passing water molecule

Hydrogen Ion, H plus, or Proton

The names for H⁺

Acid

A chemical compound that dissociates into one or more hydrogen ions (H+) and one or more negative ions, or anions. An acid donates H+ ions to solutions.

Base

Dissociates into one or more positive ions, cations, and one or more hydroxide ions (OH-). Acceots H+ ions which reduce the hydrogen ion concentration of a solution

Neutral Substances

Neither acidic nor masic, such as distilled water or NaCl

pH

A measure of the acidity of basicity of an aqueous solution, or a measure of the concentration of H+ ions.

Buffers

Substances that have the ability to resist or minimize sudden changes to the original pH of a solution.