Podcast
Questions and Answers
What exists in a system of at least 2 states when the populations of the two states are constant?
What exists in a system of at least 2 states when the populations of the two states are constant?
Equilibrium
What does Le Châtelier's Principle state?
What does Le Châtelier's Principle state?
- Systems will always strive to create new substances.
- Systems will always strive to reestablish the state of equilibrium. (correct)
- Equilibrium is only achieved by adding reactants.
- Changing pressure has no effect on equilibrium.
What is the equilibrium constant (K)?
What is the equilibrium constant (K)?
A numerical description of the balance of reactants and products in molar concentrations.
What does an acid do according to the Bronsted definition?
What does an acid do according to the Bronsted definition?
A conjugate base can only accept a hydrogen ion if it contains a hydroxide anion.
A conjugate base can only accept a hydrogen ion if it contains a hydroxide anion.
Which of the following describes an amphiprotic species?
Which of the following describes an amphiprotic species?
What type of solution is a pH buffer?
What type of solution is a pH buffer?
What happens when a strong acid is added to a buffered solution?
What happens when a strong acid is added to a buffered solution?
How do weak acids behave in water?
How do weak acids behave in water?
Flashcards are hidden until you start studying
Study Notes
Chemical Equilibria
- Equilibrium occurs when populations of at least two states remain constant in a system.
- Chemical reactions are typically reversible, allowing reactants to form products and vice versa.
- The use of double arrows indicates a reversible and equilibrating process.
Le Châtelier’s Principle
- Systems attempt to restore equilibrium when disturbed.
- Adding reactants shifts equilibrium toward products; adding products shifts it toward reactants.
- In the alveoli, high oxygen tension promotes oxygen binding to hemoglobin, while low tissue concentration facilitates release.
- Changes in volume and pressure also affect equilibrium; increasing FiO2 increases dissolved oxygen levels.
Equilibrium Constant
- The equilibrium constant (K) quantifies the ratio of reactant and product concentrations at equilibrium.
- For a reaction aA + bB ⇌ cC + dD, K is expressed as K = [D]d[C]c / [A]a[B]b.
- Specific constants, like Ka, indicate the equilibrium of weak acid ionization.
- A K value greater than 1 indicates a product-favored reaction.
Acids and Bases
- Acids increase H+ concentration; in water, H+ exists as hydronium ions (H3O+).
- Bases raise hydroxide ion (OH-) levels in aqueous solutions.
- According to the Brønsted definition, acids donate H+ to bases which accept it.
- In the reaction HCl → H+ + Cl-, H+ is the acid and Cl- is a conjugate base that can accept H+.
- Amphiprotic species, like bicarbonate (HCO3-), can act as acids or bases, exemplifying polyprotic acids that can release multiple H+ ions.
- Weak acids establish a dynamic equilibrium when dissolved in water; their strength is indicated by Ka, reflecting the degree of H+ donation.
- Example: For carbonic acid (H2CO3), Ka = 7.94x10^-7, and pKa is calculated using pKa = -log(Ka), resulting in pKa of 6.1.
Buffers
- pH buffers resist changes in pH by containing a weak acid (HA) and its conjugate base (A-).
- When strong acids are introduced to a buffered solution, the weak base (A-) neutralizes it to form the weak acid (HA).
- In the presence of strong bases, the weak acid (HA) reacts to produce water and the weak base (A-), maintaining pH stability.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
