What is the state of a chemical reaction at equilibrium?
ARate of forward reaction is greater than reverse reaction
BRate of reverse reaction is greater than forward reaction
CRate of forward reaction equals rate of reverse reaction
DReaction stops completely
At equilibrium, the rate of the forward reaction is equal to the rate of the reverse reaction, leading to no net change in the concentration of reactants and products over time.
ChemistryEquilibriumEasy#72
Which of the following is true for a system at equilibrium?
AThe concentrations of reactants and products are equal
BThe concentrations of reactants and products are constant
CThe reaction stops
DOnly products are present
At equilibrium, the concentrations of reactants and products remain constant over time, though they are not necessarily equal. The reaction continues at equal rates in both directions.
ChemistryEquilibriumEasy#73
What does the equilibrium constant (K) represent?
AThe rate of the forward reaction
BThe rate of the reverse reaction
CThe ratio of concentrations of products to reactants at equilibrium
DThe difference between product and reactant concentrations
The equilibrium constant (K) is the ratio of the concentrations of products to reactants at equilibrium, each raised to the power of their stoichiometric coefficients.
ChemistryEquilibriumEasy#74
For a reaction, if K > 1, it indicates that:
AReactants are favored
BProducts are favored
CReaction is at equilibrium
DReaction does not occur
If K > 1, the concentration of products is greater than that of reactants at equilibrium, indicating that the reaction favors the formation of products.
ChemistryEquilibriumEasy#75
Which of the following does not affect the equilibrium position of a reaction?
ATemperature
BPressure
CConcentration
DCatalyst
A catalyst speeds up the rate of both forward and reverse reactions equally, thus it does not affect the equilibrium position; it only helps the system reach equilibrium faster.
ChemistryEquilibriumEasy#76
What happens to the equilibrium when temperature is increased for an exothermic reaction?
AShifts to the right
BShifts to the left
CNo change
DReaction stops
For an exothermic reaction, increasing temperature favors the reverse reaction (endothermic), shifting the equilibrium to the left to absorb the added heat.
ChemistryEquilibriumEasy#77
Le Chatelier’s principle states that:
AA system at equilibrium cannot be disturbed
BA system at equilibrium adjusts to minimize disturbances
CEquilibrium is achieved only at high pressure
DEquilibrium depends only on temperature
Le Chatelier’s principle states that if a system at equilibrium is disturbed by a change in conditions, it will adjust to counteract the disturbance and restore equilibrium.
ChemistryEquilibriumEasy#78
What is the unit of equilibrium constant (K) for a reaction with equal moles of reactants and products?
Amol/L
BL/mol
CNo unit
Dmol²/L²
If the number of moles of reactants and products are equal in a balanced equation, the equilibrium constant (K) has no unit since the concentration terms cancel out.
ChemistryEquilibriumEasy#79
What effect does increasing pressure have on a gaseous equilibrium reaction with more moles of reactants than products?
AShifts to the right
BShifts to the left
CNo effect
DReaction stops
Increasing pressure shifts the equilibrium towards the side with fewer moles of gas. If there are more moles of reactants, the equilibrium shifts to the left.
ChemistryEquilibriumEasy#80
Which of the following is a characteristic of a dynamic equilibrium?
AReactions stop completely
BForward and reverse reactions occur at the same rate
COnly forward reaction occurs
DOnly reverse reaction occurs
Dynamic equilibrium is characterized by the forward and reverse reactions occurring at the same rate, resulting in no net change in the system.