1 Omar is learning about reversible reactions. He learns that the reaction: 2SO2 + O2 ⇌ 2SO3 is reversible. What happens if SO3 is removed from the system? A The equilibrium shifts to the left B The equilibrium shifts to the right C The reaction stops D There is no effect
2 Fatima is studying the conditions for equilibrium. She understands that for a reaction to be at equilibrium, the forward and reverse reactions must have the same rate. What happens to the concentrations of reactants and products when the rates are equal? A They are equal B They are constant C They are zero D They are increasing
3 Which factor does NOT affect the position of equilibrium? A Temperature B Pressure C Concentration D Catalyst
4 Which of the following is a characteristic of equilibrium? A Occurs in open system B Rate of reaction is zero C Observable properties remain constant D Products stop reacting
5 If equilibrium constant equals 1, it means: A Reaction goes to completion B Reactants are favored C Products and reactants are equally favored D No reaction occurs
6 Aisha is learning about dynamic equilibrium. She understands that at equilibrium, the system is in a state of balance. Which of the following statements is true about dynamic equilibrium? A It occurs only in irreversible reactions B It occurs only in reversible reactions C It occurs in all reactions D It occurs only in biological systems
7 Zayn is studying chemical equilibrium. He learns that the equilibrium constant (K) for a reaction is constant at a given temperature. If K is very large, what does it indicate about the reaction? A The reaction proceeds almost to completion B The reaction hardly proceeds at all C The reaction is in the middle D The reaction is very slow
8 Paula is studying chemical equilibrium. She understands that equilibrium can be affected by changes in concentration, temperature, and pressure. What is the principle that predicts the direction of the shift? A The law of conservation of mass B Le Chatelier's principle C The law of definite proportions D The law of multiple proportions
9 Which statement about equilibrium is correct? A Equilibrium means reaction stops B Equilibrium can occur in open systems C Equilibrium is dynamic D Equilibrium favors reactants always
10 The study of chemical equilibrium helps in understanding: A Atomic structure B Reaction yield C Isotopes D Radioactivity
11 Pure solids are not included in equilibrium expressions because: A They do not react B Their concentration is constant C They are catalysts D They have no mass
12 If the equilibrium constant is very small, the reaction favors: A Products B Reactants C Both equally D Completion
13 Fatima is studying the concept of dynamic equilibrium. She learns that at equilibrium, the macroscopic properties of the system are constant. Which of the following is a macroscopic property that remains constant at equilibrium? A Temperature B Pressure C Color D All of the above
14 Laura is studying chemical equilibrium. She learns that the equilibrium constant (K) is a measure of the extent of a reaction. What does a small equilibrium constant (K << 1) indicate? A The equilibrium favors the reactants B The equilibrium favors the products C The reaction is very fast D The reaction is irreversible
15 Paula is studying the effect of temperature on equilibrium. She knows that for an exothermic reaction, increasing temperature shifts the equilibrium to the left. Why does this happen? A Because the reverse reaction is endothermic and absorbs heat B Because the forward reaction is endothermic C Because temperature has no effect D Because the reverse reaction is exothermic
16 For the reaction N2 + 3H2 ⇌ 2NH3, the equilibrium expression is: A [N2][H2]3 / [NH3]2 B [NH3]2 / [N2][H2]3 C [NH3] / [N2][H2] D [N2] / [NH3]
17 Decrease in temperature favors: A Endothermic reaction B Exothermic reaction C Both equally D No change
18 The unit of equilibrium constant depends on: A Temperature B Balanced equation C Pressure only D Catalyst
19 Carlos is learning about chemical equilibrium. He understands that the equilibrium constant (K) depends on temperature. If the temperature of an exothermic reaction is increased, what happens to the value of K? A K increases B K decreases C K remains the same D K becomes zero
20 Ibrahim is learning about reversible reactions. He understands that the reaction: N2 + 3H2 ⇌ 2NH3 is reversible. What happens if the pressure is increased on this system? A The equilibrium shifts to the left (towards reactants) B The equilibrium shifts to the right (towards products) C There is no effect D The reaction stops
21 Ibrahim is learning about the conditions for equilibrium. He understands that temperature can affect the position of equilibrium. According to Le Chatelier's principle, how does an increase in temperature affect an endothermic reaction? A It shifts the equilibrium to the left B It shifts the equilibrium to the right C It has no effect D It stops the reaction
22 Which reaction is endothermic? A Heat is released B Heat is absorbed C No heat change D Always reversible
23 Removal of products shifts equilibrium toward: A Reactants B Products C No change D Stopping reaction
24 Which condition increases the value of equilibrium constant? A Change in pressure B Change in concentration C Change in temperature D Addition of catalyst
25 Xia is studying the conditions for equilibrium. She learns that equilibrium is a dynamic process. Which of the following is an example of a system at dynamic equilibrium? A A sealed container of water and ice at 0°C B A burning candle C A piece of iron rusting D A glass of soda losing its fizz
26 Rania is studying the concept of chemical equilibrium. She learns that equilibrium can be disturbed by changing conditions. According to Le Chatelier's principle, what happens when a system at equilibrium is disturbed? A It remains unchanged B It shifts to counteract the disturbance C It shifts to amplify the disturbance D It breaks down completely
27 In dynamic equilibrium: A No reaction occurs B Only forward reaction occurs C Both reactions continue at equal rates D Only reverse reaction occurs
28 Equilibrium constant is independent of: A Temperature B Catalyst C Nature of reaction D Stoichiometry
30 Khalid is learning about the conditions for equilibrium. He knows that a catalyst does not affect the equilibrium position. Why is a catalyst useful in industrial processes involving equilibrium? A It shifts the equilibrium to favor products B It increases the rate at which equilibrium is reached C It decreases the yield of products D It changes the equilibrium constant