1 The branch of chemistry that deals with the study of substances found in living organisms is: A Organic chemistry B Inorganic chemistry C Biochemistry D Analytical chemistry
2 In a chemical equation, the substances on the left side of the arrow are called: A Products B Reactants C Catalysts D Inhibitors
3 The relative atomic mass of an element is the weighted average of the masses of its: A Ions B Isotopes C Molecules D Compounds
4 Which of the following is an exception in covalent compounds regarding electrical conductivity? A Water B Graphite C Methane D Carbon dioxide
5 The percentage yield of a reaction is calculated by: A Actual yield / Theoretical yield × 100 B Theoretical yield / Actual yield × 100 C Actual yield × Theoretical yield × 100 D Actual yield + Theoretical yield × 100
6 آئینی مرکب کی فارمولا اکائی کیا ہے؟ A سب سے چھوٹی دہرائی جانے والی اکائی جو آئنوں کا تناسب ظاہر کرے B دو غیر دھاتوں سے بنا مالیکیول C ایک آئن کی کمیت D ایک مول میں آئنوں کی تعداد
7 The relative atomic mass of an element is the: A sum of masses of all isotopes B weighted average of the masses of its isotopes C mass of the most abundant isotope D mass of the lightest isotope
8 Which of the following is the correct name for N2O? A Dinitrogen monoxide B Nitrogen oxide C Nitrogen dioxide D Dinitrogen trioxide
9 The relative atomic mass of an element is the weighted average of the masses of its isotopes relative to: A Carbon-12 atom B Hydrogen-1 atom C Oxygen-16 atom D Nitrogen-14 atom
10 The formula for relative atomic mass is: A Sum of (isotopic mass × abundance) ÷ 100 B Sum of masses of protons and electrons C Mass number × atomic number D Neutrons ÷ protons
11 The solubility of a gas in a liquid generally ______ with an increase in temperature. A increases B decreases C remains the same D first increases then decreases
12 Which of the following is an example of a chemical change? A Dissolving sugar in water B Boiling of water C Rusting of iron D Breaking of glass
13 The relative atomic mass of chlorine is 35.5 u. This value is actually the: A Mass number of chlorine-35 B Mass number of chlorine-37 C Weighted average of the masses of chlorine-35 and chlorine-37 D Simple average of the masses of chlorine-35 and chlorine-37
14 The relative atomic mass of an element is calculated relative to which standard? A Carbon-12 B Oxygen-16 C Hydrogen-1 D Nitrogen-14
15 Which of the following is the correct name for the compound N₂O? A Nitrogen oxide B Dinitrogen monoxide C Nitrogen monoxide D Dinitrogen oxide
16 The isotope of hydrogen that has one proton and two neutrons is called: A Protium B Deuterium C Tritium D Hydride
17 In a balanced chemical equation, what does the law of conservation of mass imply? A The total mass of reactants is greater than the products. B The total mass of reactants is equal to the total mass of products. C The total mass of products is greater than the reactants. D Mass is lost during the reaction.
18 The molecular formula of a compound is a whole-number multiple of its empirical formula. What is this whole number called? A n-factor B mole ratio C Avogadro number D molar mass
19 Which of the following substances is likely to have a giant covalent structure? A Sodium chloride B Diamond C Water D Carbon dioxide
20 Percentage yield is calculated as: A (Actual yield / Theoretical yield) × 100 B (Theoretical yield / Actual yield) × 100 C (Actual yield × Theoretical yield) × 100 D (Actual yield + Theoretical yield) × 100
21 Ionic bonds are formed by: A Sharing of electrons B Transfer of electrons C Overlap of orbitals D Delocalization of electrons
22 Which type of reaction is represented by: A + B → AB? A Decomposition B Combination C Single displacement D Double displacement
23 A solution that contains the maximum amount of solute that can dissolve at a given temperature is called: A Unsaturated solution B Saturated solution C Supersaturated solution D Dilute solution
24 What is the approximate particle size of a colloidal solution? A Less than 1 nm B 1 nm to 1000 nm C More than 1000 nm D Exactly 1 cm
25 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