1 For an endothermic reaction at equilibrium, increasing the temperature will: A Shift equilibrium to the right B Shift equilibrium to the left C Decrease the equilibrium constant D Have no effect
2 Which gas is mainly responsible for acid rain? A Carbon dioxide B Sulfur dioxide C Oxygen D Nitrogen
3 لوشاتیلیے کے اصول کے مطابق کسی ری ایکٹنٹ کی مقدارِ ارتکاز بڑھانے سے توازن کس طرف منتقل ہوگا؟ A ری ایکٹنٹس کی طرف B مصنوعات کی طرف C کوئی تبدیلی نہیں ہوگی D صرف عمل انگیز کی طرف
4 Dynamic equilibrium is reached when: A forward and backward rates become equal B forward reaction stops completely C backward reaction stops completely D concentrations of reactants and products become zero
5 In a reversible reaction at equilibrium, the concentrations of reactants and products: A Keep changing continuously B Become zero C Remain constant D Become equal to each other
6 Which gas is a major cause of acid rain along with sulfur dioxide? A Carbon dioxide B Nitrogen oxides C Oxygen D Helium
7 Which of the following is a property of metals? A Poor conductors of heat B Brittle and hard C Good conductors of electricity D Low melting points
8 According to Le Chatelier's principle, decreasing the concentration of a product will: A Shift equilibrium to the left B Shift equilibrium to the right C Have no effect D Increase the equilibrium constant
9 How many moles are present in 36 g of water? (H₂O = 18 g/mol) A 2 moles B 1 mole C 0.5 mole D 4 moles
10 Acid rain is mainly caused by the presence of which gases in the atmosphere? A CO2 and O2 B SO2 and NOx C CH4 and H2 D N2 and O2
11 In the notation 35/17 Cl, the number 17 represents the: A mass number B atomic number C number of neutrons D number of nucleons
12 Which one is a characteristic of irreversible reactions? A They go only in the forward direction. B They always reach equilibrium. C They use a double arrow. D They occur in closed systems only.
13 Which reaction represents neutralization? A Acid + metal → salt + hydrogen B Acid + base → salt + water C Acid + carbonate → salt + water + CO₂ D Base + metal → salt + hydrogen
14 Ionic compounds conduct electricity when: A Solid B Molten or dissolved in water C Crystalline D Mixed with sugar
15 A catalyst increases the rate of a reversible reaction by: A Increasing the temperature B Lowering the activation energy C Changing the equilibrium constant D Increasing the concentration
16 Which separation technique is used to separate a mixture of salt and water? A Filtration B Distillation C Evaporation D Chromatography
17 Increasing the concentration of a reactant in an equilibrium mixture will: A shift equilibrium to the right B shift equilibrium to the left C stop the forward reaction D have no effect on equilibrium
18 In a coordinate covalent bond, the shared electron pair is donated by: A Both atoms equally B One atom only C The nucleus D A third atom
19 In a physical equilibrium, which of the following remains constant? A Rate of forward reaction only B Rate of reverse reaction only C Both rates are equal and concentrations remain constant D Temperature
21 Which factor does NOT affect the rate of a chemical reaction? A Temperature B Concentration of reactants C Surface area of solid reactants D Enthalpy change of the reaction
22 According to the Lewis concept, a base is a: A Proton donor B Proton acceptor C Electron pair donor D Electron pair acceptor
23 Which type of system can exchange both matter and energy with its surroundings? A Open system B Closed system C Isolated system D Adiabatic system
24 The solubility of most gases in water ________ with an increase in temperature. A increases B decreases C remains constant D becomes zero
25 Which of the following is an endothermic process? A Burning of wood B Melting of ice C Respiration D Rusting of iron