This chemistry question involves key chemical concepts and calculations. The detailed solution below walks through each step, from identifying the reaction type to computing the final answer.
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Here are the solutions to your questions: 1.a) i) The gas obtained is acetylene* with the formula C_2H_2. ii) The balanced chemical equation is: CaC_2(s) + 2H_2O(l) Ca(OH)_2(aq) + C_2H_2(g) iii) Calculate the mass of slaked lime obtained from 2.5 g of calcium carbide. Given molar masses: Ca=40 g/mol, C=12 g/mol, H=1 g/mol, O=16 g/mol. Step 1: Calculate the molar mass of CaC_2 and Ca(OH)_2. Molar mass of CaC_2 = 40 + 2(12) = 64 g/mol Molar mass of Ca(OH)_2 = 40 + 2(16+1) = 74 g/mol Step 2: Calculate the moles of CaC_2 used. Moles of CaC_2 = MassMolar mass = 2.5 g64 g/mol = 0.0390625 mol Step 3: Use the mole ratio from the balanced equation (CaC_2 : Ca(OH)_2 = 1:1) to find moles of Ca(OH)_2. Moles of Ca(OH)_2 = 0.0390625 mol Step 4: Calculate the mass of Ca(OH)_2 produced. Mass of Ca(OH)_2 = Moles × Molar mass = 0.0390625 mol × 74 g/mol = 2.890625 g The mass of slaked lime obtained is 2.89 g. 1.b) i) Calculate the number of Faradays used. Given: Current I = 2 A, Time t = 15 minutes. Step 1: Convert time to seconds. t = 15 min × 60 s/min = 900 s Step 2: Calculate the total charge passed. Q = I × t = 2 A × 900 s = 1800 C Step 3: Calculate the number of Faradays. (Faraday constant F ≈ 96500 C/mol) Number of Faradays = (Q)/(F) = 1800 C96500 C/mol = 0.01865 mol The number of Faradays used is 0.0187 mol. ii) Calculate the number of moles of Lithium atoms produced. The reaction at the cathode for lithium hydride electrolysis is: Li^+ + e^- Li. From the equation, 1 mole of electrons produces 1 mole of Li. Step 1: Moles of electrons passed = Number of Faradays. Moles of electrons = 0.01865 mol Step 2: Calculate moles of Lithium produced. Moles of Li = Moles of electrons = 0.01865 mol The number of moles of Lithium atoms produced is 0.0187 mol. iii) Calculate the volume of gas produced at r.t.p. The gas produced at the anode from lithium hydride electrolysis is hydrogen: 2H^- H_2 + 2e^-. From the equation, 2 moles of electrons produce 1 mole of H_2. Step 1: Calculate moles of H_2 gas produced. Moles of H_2 = Moles of electrons2 = 0.01865 mol2 = 0.009325 mol Step 2: Calculate the volume of H_2 gas at r.t.p. (Molar volume at r.t.p = $2400 cm^3/