equilibrium master
1.
Q: What is chemical equilibrium?
A: A state where the forward and reverse reaction rates are equal and concentrations remain constant.
2.
Q: What is the equilibrium expression for \( aA + bB \rightleftharpoons cC + dD \)?
A: K = \frac{[C]^c[D]^d}{[A]^a[B]^b}
3.
Q: What substances are omitted from equilibrium expressions?
A: Pure solids and pure liquids.
4.
Q: What is the difference between K_c and K_p?
A: K_c uses concentrations (mol/L); K_p uses partial pressures (atm).
5.
Q: What is the reaction quotient Q?
A: Same as K, but uses initial or current concentrations.
6.
Q: What does it mean if Q < K?
A: The reaction shifts right to form more products.
7.
Q: What does it mean if Q > K?
A: The reaction shifts left to form more reactants.
8.
Q: What is an ICE table used for?
A: To organize Initial, Change, and Equilibrium concentrations.
9.
Q: What is Le Châtelier’s Principle?
A: A system at equilibrium shifts to oppose changes in concentration, pressure, or temperature.
10.
Q: How does increasing reactant concentration affect equilibrium?
A: Shifts right (toward products).
11.
Q: How does increasing product concentration affect equilibrium?
A: Shifts left (toward reactants).
12.
Q: How does pressure change affect equilibrium in gas reactions?
A: Increase in pressure shifts toward fewer gas moles; decrease shifts toward more.
13.
Q: What effect does a catalyst have on equilibrium position?
A: None. It only speeds up reaching equilibrium.
14.
Q: How does temperature affect equilibrium for exothermic reactions?
A: Increasing temperature shifts left (heat is a product).
15.
Q: How does temperature affect equilibrium for endothermic reactions?
A: Increasing temperature shifts right (heat is a reactant).
16.
Q: What is the formula relating K_p and K_c?
A: K_p = K_c(RT)^{\Delta n}
17.
Q: In the equation K_p = K_c(RT)^{\Delta n}, what is \Delta n?
A: The change in gas moles: \text{mol products} - \text{mol reactants}
18.
Q: What is the relationship between Gibbs Free Energy and K?
A: \Delta G^\circ = -RT \ln K
19.
Q: If \Delta G^\circ < 0, what does that say about K?
A: K > 1; products are favored.
20.
Q: If \Delta G^\circ > 0, what does that say about K?
A: K < 1; reactants are favored.
21.
Q: What are the steps to solve an equilibrium problem with unknown concentrations?
A: Write the equation, set up ICE table, use the K expression, solve for x, calculate concentrations.
22.
Q: What is the only factor that changes the value of K?
A: Temperature
23.
Q: What does it mean when Q = K?
A: The system is already at equilibrium.
24.
Q: Why is it important to use Kelvin in equilibrium equations?
A: Thermodynamic equations like \Delta G = -RT \ln K require absolute temperature.
25.
Q: What mistake should you avoid in writing equilibrium expressions?
A: Including solids or liquids, or incorrect stoichiometric exponents.