1 Samir is learning about reversible reactions. He learns that a reversible reaction reaches equilibrium when the rates of the forward and reverse reactions are equal. What is the effect of increasing the concentration of a reactant on the forward reaction rate? A It increases B It decreases C It remains the same D It stops
2 Emma is learning about the equilibrium condition. She understands that for equilibrium to be established, the reaction must be reversible. Which of the following is a characteristic of a reversible reaction? A It can proceed in only one direction B It can proceed in both forward and reverse directions C It is always fast D It is always slow
3 Khalid is learning about dynamic equilibrium. He knows that at equilibrium, the forward and reverse reactions continue to occur. What is the net change in concentrations of reactants and products at equilibrium? A Positive B Negative C Zero D Variable
4 According to Bronsted–Lowry theory, a base is a: A Proton donor B Proton acceptor C Neutron donor D Electron acceptor
5 Increase in concentration of reactants shifts equilibrium toward: A Left B Right C No change D Completion
7 Lara is studying basic oxides. She knows that basic oxides react with water to form bases. Which of the following is a basic oxide? A CO2 B SO2 C CaO D P2O5
8 Rachel is studying the strength of bases. She knows that weak bases partially ionize in water. Which of the following is a weak base? A NaOH B KOH C NH3 D Ca(OH)2
9 Nadia is studying dynamic equilibrium. She understands that at equilibrium, the macroscopic properties are constant. Which of the following is a macroscopic property that would be constant at equilibrium? A Mass of reactants B Total pressure C Concentration of a specific reactant D All of the above
10 David is studying the Arrhenius concept. He knows that an acid produces H+ ions in water. Which of the following is an acid according to Arrhenius? A H2O B HCl C NaOH D NH3
11 Mohamed is learning about the conditions for equilibrium. He knows that concentration of reactants and products can affect the equilibrium position. According to Le Chatelier's principle, increasing the concentration of a reactant will: A Shift the equilibrium to the left B Shift the equilibrium to the right C Have no effect D Stop the reaction
13 Fatima is studying strong acids. She knows that strong acids completely ionize in water. Which of the following is a strong acid? A HNO3 B H2CO3 C H3PO4 D CH3COOH
14 Hina is studying reversible reactions. She learns that not all reactions are reversible. Which of the following is an example of a reaction that is reversible? A Burning of wood B Decomposition of calcium carbonate (CaCO3 ⇌ CaO + CO2) C Rusting of iron D Digestion of food
15 Tina is studying chemical equilibrium. She learns that equilibrium can be affected by temperature changes. What happens to the equilibrium position if the temperature of an endothermic reaction is increased? A It shifts to the left B It shifts to the right C It has no effect D It depends on the pressure
16 Hina is studying chemical equilibrium. She learns that the equilibrium constant (K) is temperature-dependent. What happens to K for an exothermic reaction when the temperature is decreased? A K increases B K decreases C K remains the same D K becomes infinite
17 Yara is learning about Le Chatelier's principle. She knows that adding a catalyst to a system at equilibrium will not shift the equilibrium. Why is a catalyst used in industrial processes then? A To increase the yield of products B To speed up the attainment of equilibrium C To shift the equilibrium to the right D To shift the equilibrium to the left
18 Waseem is studying weak acids. He knows that weak acids partially ionize in water. Which of the following is a weak acid? A HNO3 B HCl C H2SO4 D CH3COOH
19 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
20 Uma is learning about the concept of acids and bases. She knows that according to the Arrhenius concept, acids produce H+ ions in water. Which of the following is an Arrhenius acid? A H2SO4 B NaOH C NH3 D NaCl
21 Which change shifts equilibrium to the right? A Increase in product concentration B Decrease in reactant concentration C Increase in reactant concentration D Addition of catalyst
22 Which condition increases the value of equilibrium constant? A Change in pressure B Change in concentration C Change in temperature D Addition of catalyst
23 At equilibrium, the rate of forward reaction is: A Greater than reverse B Less than reverse C Equal to reverse D Zero
25 Which salt is formed by strong acid and strong base? A Acidic salt B Basic salt C Neutral salt D Complex salt