1 The sharing of one pair of electrons forms a: A Double bond B Triple bond C Single bond D Ionic bond
2 Uma is studying the role of catalysts in industrial processes. She knows that catalysts are used in the Haber process and contact process. What is the catalyst used in the contact process for making sulfuric acid? A Iron B Vanadium pentoxide C Platinum D Nickel
3 Xia is learning about the octet rule. She understands that atoms tend to achieve eight electrons in their valence shell. Which of the following elements satisfies the octet rule in its most common state? A Hydrogen B Helium C Neon D Lithium
5 Ibrahim is studying gram molecular mass. He knows that the gram molecular mass of a compound is the mass of one mole of molecules of that compound. What is the gram molecular mass of CO2? (C=12, O=16) A 28 g B 44 g C 56 g D 72 g
6 Nadia is studying the conduction of electricity through acids. She learns that acids conduct electricity when dissolved in water. What is the reason for this conduction? A Presence of free electrons B Presence of free ions C Presence of free atoms D Presence of free molecules
7 Chloe is learning about chemical bonds. She understands that bonds form when atoms gain, lose, or share electrons. Which type of bond is formed when electrons are transferred from one atom to another? A Covalent bond B Ionic bond C Metallic bond D Hydrogen bond
8 Victor is studying exothermic reactions. He knows that combustion reactions are exothermic. Which of the following is an example of a combustion reaction? A Photosynthesis B Burning of methane C Dissolving ammonium nitrate in water D Electrolysis of water
10 Julia is studying respiration. She knows that aerobic respiration requires oxygen, while anaerobic respiration does not. Which type of respiration produces more energy (ATP)? A Anaerobic respiration B Aerobic respiration C Both produce equal energy D Neither produces energy
11 Reduction is defined as: A Loss of electrons B Gain of electrons C Loss of oxygen D Gain of protons
12 Zayn is learning about the arrangement of particles in different substances. He knows that in ionic compounds, particles are arranged in a regular, repeating pattern called a crystal lattice. What is the arrangement of particles in a metallic crystal? A Molecules in a lattice B Atoms or ions in a sea of electrons C Covalent network D Individual molecules
13 Omar is learning about intermolecular forces and their influence on melting and boiling points. He understands that stronger intermolecular forces lead to higher boiling points. Which of the following has the highest boiling point due to hydrogen bonding? A H2O B H2S C HCl D CH4
14 George is studying bond formation and bond dissociation. He knows that energy is released when bonds are formed and energy is absorbed when bonds are broken. What is the term for the energy required to break a bond? A Bond formation energy B Bond dissociation energy C Activation energy D Enthalpy change
15 Which bond is formed due to electrostatic attraction? A Covalent bond B Ionic bond C Hydrogen bond D Single bond
16 Victor is balancing the equation: N2 + H2 → NH3. What is the correct balanced equation? A N2 + 3H2 → 2NH3 B N2 + H2 → NH3 C 2N2 + H2 → 2NH3 D N2 + 2H2 → NH3
17 Samir is learning about the properties of diamond. He knows that diamond is the hardest natural substance. Why is diamond so hard? A Because of weak intermolecular forces B Because of strong covalent bonds in a three-dimensional network C Because of metallic bonds D Because of ionic bonds
18 Ibrahim is learning about coordinate covalent bonds. He understands that in this type of bond, both electrons are supplied by one atom. Which of the following involves a coordinate covalent bond? A NH4+ B NaCl C MgO D Al2O3
19 Zara has 5 moles of NaCl. How many formula units of NaCl does she have? A 3.011 × 10^24 formula units B 6.022 × 10^23 formula units C 1.204 × 10^24 formula units D 1.806 × 10^24 formula units
20 Nadia is contrasting ionic and covalent compounds. She learns that covalent compounds are usually poor conductors of electricity. Why are covalent compounds poor conductors? A Because they have free electrons B Because they do not have free ions or electrons C Because they have ionic bonds D Because they have metallic bonds
21 David is studying thermochemical equations. He writes the equation: C(s) + O2(g) → CO2(g) ΔH = -393.5 kJ. What does the negative ΔH indicate? A The reaction is endothermic B The reaction is exothermic C The reaction is at equilibrium D The reaction requires a catalyst
22 Victor is calculating the gram molecular mass of nitrogen gas (N2). He knows N=14. What is the gram molecular mass of N2? A 14 g B 28 g C 56 g D 7 g
23 Usman is learning about the formula of ionic compounds. He knows that the formula is written by balancing the charges. What is the formula of the ionic compound formed between calcium (Ca2+) and phosphate (PO4^3-)? A CaPO4 B Ca3(PO4)2 C Ca2(PO4)3 D Ca(PO4)2
24 Which process converts electrical energy into chemical energy? A Voltaic cell B Electrolytic cell C Fuel cell D Dry cell
25 Qasim is studying the nature of bonding and structure. He learns that the structure of a substance determines its properties. Which type of structure does sodium chloride have? A Giant covalent structure B Giant ionic lattice C Simple molecular structure D Metallic structure
27 Samir is studying the arrangement of particles in different types of bonding. He knows that in covalent bonding, atoms share electrons. What is the arrangement of particles in a molecular covalent substance? A Giant lattice of atoms B Distinct molecules held by weak forces C Giant lattice of ions D Sea of electrons
28 Sam is studying the effect of temperature on reaction rate. He knows that increasing temperature increases the rate of reaction. Why does this happen? A Because more molecules have energy greater than activation energy B Because the enthalpy change becomes more negative C Because the catalyst becomes more active D Because the bond dissociation energy decreases
29 George is studying respiration. He knows that aerobic respiration is more efficient than anaerobic respiration. How many ATP molecules are produced from one glucose molecule in aerobic respiration? A 2 ATP B 36-38 ATP C 4 ATP D 12 ATP
30 A balanced chemical equation follows the law of: A Constant proportion B Multiple proportion C Conservation of mass D Definite composition