State and change of substances revision

all more difficult / unfamiliar terms and concepts!

Law of conservation of mass

In any chemical reaction, mass is conserved; the number of atoms for each element must be the same on both sides of the equation

Acid

Substance that donates protons (H⁺ ions)

Can also be defined as a substance without hydrogen, that accepts electrons

• increase the concentration of hydrogen ions in solutions

• pH less than 7

• after “donating” becomes a conjugate base, since it could gain the proton back

Base

Substance that accepts protons (H⁺ ions) and often releases hydroxide ions (OH^- ) in water

• could also be a substance without Hydrogen, where a base is defined as a substance that donates electrons

• after receiving a proton, it becomes a conjugate acid, since it could lose the proton.

pH scale

Scale that measures how acidic or basic a solution is

• 0-6 acidic

• 7 neutral

• 8-14 basic

the scale is logarithmic, meaning that each one unit change in pH represents a 10x change in the concentration of hydrogen ions