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.
ScanSolve AI Answer
Here are the calculations for question 1(b). Step 1: Calculate the molar mass of NaHCO₃. The atomic masses are given as H = 1.0, C = 12.0, O = 16.0, Na = 23.0. Molar mass of NaHCO_3 = (23.0 × 1) + (1.0 × 1) + (12.0 × 1) + (16.0 × 3) Molar mass of NaHCO_3 = 23.0 + 1.0 + 12.0 + 48.0 = 84.0 g/mol Step 2: Calculate the number of moles of NaHCO₃ (B). The mass of NaHCO₃ is 2.10 g. Moles of NaHCO_3 = MassMolar mass = 2.10 g84.0 g/mol = 0.025 mol Step 3: Calculate the concentration of B in mol dm⁻³. The volume of solution B is 250 cm³, which is equal to 250 cm^3 × 1 dm^31000 cm^3 = 0.250 dm^3. Concentration of B = MolesVolume (dm^3) = 0.025 mol0.250 dm^3 = 0.10 mol dm^-3 To calculate parts (ii), (iii), and (iv), the average volume of solution A used in the titration (from part 1(a)) is required, as well as the specific volume of solution B used for each titration (either 20.0 cm³ or 25.0 cm³). Since these values are not provided in the question, we will assume the following to demonstrate the calculations: Assume 25.0 cm³ of solution B was used for each titration. Assume the average volume of solution A used was 24.50 cm³. Step 4: Calculate the concentration of A in mol dm⁻³ (based on assumptions). From the balanced equation: NaHCO_3(aq) + HCl(aq) → NaCl(aq) + H_2O(l) + CO_2(g). The mole ratio of NaHCO₃ to HCl is 1:1. Moles of NaHCO₃ in 25.0 cm³ of solution B: Moles of NaHCO_3 = Concentration of B × Volume of B Moles of NaHCO_3 = 0.10 mol dm^-3 × (25.0)/(1000) dm^3 = 0.0025 mol Since the mole ratio is 1:1, moles of HCl reacted = 0.0025 mol. Concentration of A (HCl): Concentration of A = Moles of HClAverage volume of A (dm^3) Concentration of A = 0.0025 mol(24.50)/(1000) dm^3 = (0.0025)/(0.0245) mol dm^-3 ≈ 0.102 mol dm^-3 Step 5: Calculate the concentration of A in g dm⁻³ (based on assumptions). Molar mass of HCl = H + Cl = 1.0 + 35.5 = 36.5 g/mol. Concentration of A in g dm^-3 = Concentration of A in mol dm^-3 × Molar mass of HCl Concentration of A in g dm^-3 = 0.102 mol dm^-3 × 36.5 g/mol ≈ 3.72 g dm^-3 Step 6: Calculate the volume, V, of hydrogen chloride gas dissolved in 1 dm³ of the solution (based on assumptions). The concentration of A in mol dm⁻³ represents the moles of HCl in 1 dm³ of solution. Moles of HCl in 1 dm³ of solution A = 0.102 mol. Molar volume of gas at s.t.p. = 22.4 dm³/mol. Volume of HCl gas = Moles of HCl × Molar volume of gas at s.t.p. Volume of HCl gas = 0.102 mol × 22.4 dm^3/mol ≈ 2.28 dm^3 Drop the next question. 🧪