Chemical Reactions and Equations
10 solved questions from Class 10 Science, each with the full working. Tap any question to see the step-by-step solution.
- 1 A 2.00 L bottle contains oxygen gas at STP. It is used to completely combust methane according to the reaction CH_4 + 2O_2 → CO_2 + 2H_2O. Assuming complete consumption of the oxygen, calculate (a) the volume of methane required, (b) the volume of carbon dioxide produced, both at STP. (Take 1 mol gas = 22.4 L at STP.) hard 5 marks Gas volume calculations using stoichiometry
- 2 Which of the following is the correctly balanced equation for the reaction of magnesium with oxygen to form magnesium oxide? easy MCQ 1 mark Balancing chemical equations
- 3 When 5.0 g of hydrogen gas reacts with excess oxygen at 25°C, how many grams of water are formed? (Molar mass H_2 = 2 g mol^-1, O_2 = 32 g mol^-1, H_2O = 18 g mol^-1) medium 3 marks Stoichiometry using balanced equations
- 4 State the type of chemical reaction when zinc metal reacts with hydrochloric acid to produce hydrogen gas. easy 1 mark Classification of reactions
- 5 Magnesium metal reacts with dilute sulphuric acid to produce magnesium sulphate solution and hydrogen gas. Identify the type of chemical reaction represented by this process. easy MCQ 1 mark Classification of reaction type
- 6 When 3.0 g of calcium carbonate (CaCO_3) is heated strongly, it decomposes to calcium oxide (CaO) and carbon dioxide (CO_2). Calculate the volume of CO_2 gas produced at STP. (Molar masses: CaCO_3=100 g mol^-1, CO_2=44 g mol^-1; 1 mol gas = 22.4 L at STP.) medium 3 marks Thermal decomposition stoichiometry
- 7 In acidic solution, potassium permanganate (KMnO_4) oxidises oxalic acid (H_2C_2O_4) according to the equation 2MnO_4^- + 5C_2O_4^2- + 16H^+ → 2Mn^2+ + 10CO_2 + 8H_2O. Which of the following species acts as the oxidising agent? medium MCQ 2 marks Identifying oxidising agent
- 8 Write the balanced chemical equation for the complete combustion of ethane (C_2H_6) in excess oxygen, and state the type of reaction. easy 2 marks Balancing combustion equations
- 9 What is the primary topic or theoretical principle explored in 'Chemical Reactions and Equations' (Class 10 SCIENCE)? medium MCQ Chapter Core Principle
- 10 Which key mechanism or analytical rule is highlighted in 'Chemical Reactions and Equations'? medium MCQ Key Analytical Mechanism