unit 4 Flashcards
(45 cards)
when the conditions on a system at equilibrium are changed, the system will react to reach a new equilibrium that partially reduces or counteracts the change
le chatelier’s principle
describe the development of a chemical equilibrium
The faster reaction will gradually become slower
The slower reaction will become faster
Finally, the reaction rates become equal, and the equilibrium is established
what is the effect of temperature on vapor pressure of a substance
as temperature increases, pressure increases
according to le chatelier’s principle, what does a system do when conditions on a system at equilibrium are changed
the system will react to reach a new equilibrium that partially reduces or counteracts the change
chemical equilibrium can only be reached in a ?
closed system
at when is a pH level neutral?
7
describe meaning of the pH scale. Higher pH means more ?, lower pH means more ?.
higher pH means more basic, lower pH means more acidic
How to calculate the pH from [H+] and vice versa
10 raised to the -ph
how to calculate pOH from [OH-] and vice versa
kw/h+ or 10^-14/h+ or 10^-pOH
how to calculate [H+] from [OH-] and vice versa
[H+] x [OH-] = 1 x 10^-14
how to calculate pH from pOH and vice versa
pH + pOH = 14
Definition of an acid and a base according to Bronsted-Lowry
Acids: Substances that donates a proton
Base: substances that accept a proton
what are the conditions that affect the rate of a chemical reaction
temperature, concentration, catalyst, and inhibitors
describe how temperature affects the rate of a chemical reaction
Chemical reactions are faster at higher temperatures and slower at lower temperatures
describe how concentration affects the rate of a chemical reaction
The more particles there are in a given volume, the more frequently collisions will occur and the more rapidly the reaction will take place
A third-party substance that speeds up the rate of the reaction by lowering the activation energy of the reaction, thus enabling more reactant molecules to overcome the energy barrier
catalyst
Substances interfere with a normal reaction path from reactants to products, forcing the reaction to a higher activation energy route that is slower
inhibitor
what are the 3 energy changes during a molecular collision
transition state, potential energy barrier, and activation energy
when two molecules are colliding, they form a ? that has a high potential energy at the top of the hump of the curve
transition state
the hump is a ? that must be surpassed before a collision can be effective
potential energy barrier
the minimum kinetic energy a particle must have to enter into a reaction-producing collision
activation energy
For an individual collision to result in a reaction, the particles must have:
enough kinetic energy and proper orientation
whatdoes the pH scale represent
hydrogen ion concentration
acidic solutions have more ?, meaning they have a ? pH
more H+, lower pH
