1 In the Haber process, N₂(g) + 3H₂(g) ⇌ 2NH₃(g), the reaction is exothermic. To increase the yield of ammonia, the temperature should be: A Increased B Decreased C Kept constant D Changed randomly
2 Water is called amphoteric because it can: A Only donate protons B Only accept protons C Both donate and accept protons D Neither donate nor accept protons
3 Atomic number (Z) represents the number of: A protons in the nucleus B neutrons in the nucleus C electrons and neutrons D protons and neutrons
4 Which substance is used as an indicator to test whether a solution is acidic or basic? A Sodium chloride B Litmus C Copper sulphate D Calcium carbonate
5 An ionic bond is formed when: A Two atoms share a pair of electrons B One atom donates a lone pair to another atom C Electrons are transferred from one atom to another D Metal ions are surrounded by a sea of electrons
6 According to Lewis concept, a base is a: A proton donor B proton acceptor C electron-pair acceptor D electron-pair donor
7 In anaerobic respiration in yeast, glucose is converted into: A Carbon dioxide and water B Ethanol and carbon dioxide C Lactic acid only D Oxygen and ATP
8 According to the law of conservation of mass, in a chemical reaction: A Mass is gained B Mass is lost C Mass remains constant D Mass changes unpredictably
9 In an endothermic reaction, heat is: A Released to the surroundings B Absorbed from the surroundings C Neither absorbed nor released D Converted into mass
10 Which type of bonding is present in diamond? A Ionic bonding B Metallic bonding C Giant covalent bonding D Hydrogen bonding
12 Which of the following particles was discovered by J. J. Thomson? A Proton B Neutron C Electron D Nucleus
13 The law of conservation of mass states that: A Mass can be created in a chemical reaction. B Mass can be destroyed in a chemical reaction. C Total mass of reactants equals total mass of products. D Mass changes into energy in all reactions.
14 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
15 فارمولا MgCl₂ والے مرکب کا نام کیا ہے؟ A میگنیشیم کلورائیڈ B میگنیشیم ڈائی کلورائیڈ C مینگنیز کلورائیڈ D میگنیشیم کلوریٹ
16 Which type of system allows both energy and matter to be exchanged with its surroundings? A Open system B Closed system C Isolated system D Adiabatic system
17 According to Le Chatelier's principle, what happens when the pressure is increased on a gaseous equilibrium? A The equilibrium shifts to the side with fewer moles of gas. B The equilibrium shifts to the side with more moles of gas. C The equilibrium constant always increases. D The reaction stops.
18 One control measure for acid rain is to: A Burn more fossil fuels B Reduce sulfur dioxide emissions C Increase use of coal D Release NOx into air
19 Which method is used to separate a mixture of two liquids with different boiling points? A Filtration B Distillation C Sublimation D Chromatography
20 Which of the following is an example of a physical change? A Burning of wood B Melting of ice C Rusting of iron D Digestion of food
21 For an exothermic reversible reaction at equilibrium, what happens when the temperature is increased? A The equilibrium shifts to the right. B The equilibrium shifts to the left. C The equilibrium constant increases. D The reaction rate decreases.
22 Ammonia (NH3) acts as a base because it: A Donates a proton B Accepts a proton C Donates an electron pair D Accepts an electron pair
23 Which of the following is the correct name for the compound with formula MgCl₂? A Magnesium chloride B Magnesium dichloride C Magnesium(II) chloride D Magnesium chlorate
25 For the reaction N2(g) + 3H2(g) ⇌ 2NH3(g), what is the effect of increasing pressure on the equilibrium? A It shifts to the left. B It shifts to the right. C It has no effect. D It changes the equilibrium constant.