1 What does the law of conservation of mass state? A Mass is created in a chemical reaction. B Mass is destroyed in a chemical reaction. C Mass can be converted into energy. D Mass is neither created nor destroyed in a chemical reaction.
2 What is the correct name for the compound MgCl₂? A Magnesium chloride B Magnesium dichloride C Magnesium chlorine D Magnesium chlorate
3 Which of the following is the correct name for the compound MgCl₂? A Magnesium chloride B Magnesium dichloride C Magnesium chlorate D Magnesium chlorite
4 If 4 g of hydrogen reacts with 32 g of oxygen to form water, what is the limiting reactant? (H2 + 1/2 O2 → H2O; molar masses: H2=2, O2=32) A Hydrogen B Oxygen C Water D No limiting reactant
5 Which of the following is a correct statement about the law of conservation of mass? A Mass is lost during a chemical reaction. B Mass is gained during a chemical reaction. C Total mass of reactants equals total mass of products. D Mass changes depending on the container.
6 What is the number of moles in 36 g of water? (Molar mass of H₂O = 18 g/mol) A 1 mole B 2 moles C 3 moles D 0.5 mole
7 Which formula represents the simplest whole-number ratio of atoms in a compound? A Molecular formula B Structural formula C Empirical formula D Condensed formula
8 کون سا قانون کہتا ہے کہ کیمیائی تعامل میں کمیت نہ پیدا ہوتی ہے نہ ختم ہوتی ہے؟ A کمیت کے تحفظ کا قانون B مقررہ تناسب کا قانون C متعدد تناسب کا قانون D ایووگیڈرو کا قانون
9 Which of the following is an isomer of butane (C₄H₁₀)? A 2-methylpropane B Propane C Ethene D Ethanol
10 فارمولا MgCl₂ والے مرکب کا نام کیا ہے؟ A میگنیشیم کلورائیڈ B میگنیشیم ڈائی کلورائیڈ C مینگنیز کلورائیڈ D میگنیشیم کلوریٹ
11 What is the name of the compound with formula MgCl2? A Magnesium chloride B Magnesium dichloride C Magnesium chlorine D Manganese chloride
12 The chemical formula of a compound is MgCl2. Which method is used to write this formula? A Criss-cross method B Combustion analysis C Mole ratio method D Empirical formula method
13 What is the name of the compound with formula N₂O₄? A Nitrogen tetroxide B Dinitrogen tetroxide C Nitrogen oxide D Dinitrogen oxide
14 Which type of reaction is represented by the equation: 2KClO3 → 2KCl + 3O2? A Combination B Decomposition C Single displacement D Double displacement
15 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.
16 What is the molecular formula of a compound? A The simplest whole-number ratio of atoms B The actual number of atoms of each element in one molecule C The arrangement of atoms in space D The mass of one mole of the compound
17 In the reaction N2 + 3H2 → 2NH3, how many moles of NH3 are produced from 2 moles of N2? A 2 moles B 3 moles C 4 moles D 6 moles
18 Which of the following is the correct name for the compound N₂O? A Nitrogen oxide B Dinitrogen monoxide C Nitrogen monoxide D Dinitrogen oxide
19 Which of the following is the correct name for the compound with formula N₂O₄? A Dinitrogen tetroxide B Nitrogen tetroxide C Dinitrogen oxide D Nitrogen dioxide
20 Which of the following is the correct name for the compound N₂O₄? A Dinitrogen tetroxide B Nitrogen oxide C Nitrogen tetroxide D Dinitrogen oxide
21 In a balanced chemical equation, what does the Law of Conservation of Mass state? A Mass is created during a reaction. B Mass is destroyed during a reaction. C Total mass of reactants equals total mass of products. D Mass changes into energy.
22 In the reaction N2 + 3H2 → 2NH3, if 1 mole of N2 reacts with 3 moles of H2, which reactant is the limiting reactant? A N2 B H2 C NH3 D Neither, both are in excess.
23 When writing the formula of a binary ionic compound using the criss-cross method, what is done with the charges? A They are added. B They are multiplied. C They are crossed to become subscripts. D They are ignored.
24 Which of the following is the correct name for the covalent compound N₂O₄? A Dinitrogen tetroxide B Nitrogen tetroxide C Dinitrogen tetraoxide D Nitrogen oxide
25 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