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
asanda, let's knock this out. 15.1 The reaction is exothermic. The reason is that the given enthalpy change, H < 0, indicates that the reaction releases energy to the surroundings. 15.2 Step 1: Calculate the change in mass of the tablet. Change in mass = Initial mass - Final mass Change in mass = 2 g - 0.25 g = 1.75 g Step 2: Calculate the average rate of reaction. Average rate = Change in massTime taken Average rate = 1.75 g30 s Average rate = 0.05833... g · s^-1 Average rate = 0.058 g · s^-1 15.3 Step 1: Calculate the mass of calcium carbonate (CaCO_3) in the tablet. Mass of CaCO_3 = 40\% of 2 g Mass of CaCO_3 = 0.40 × 2 g = 0.80 g Step 2: Calculate the molar mass of CaCO_3. M(CaCO_3) = M(Ca) + M(C) + 3 × M(O) M(CaCO_3) = 40.08 g/mol + 12.01 g/mol + 3 × 16.00 g/mol M(CaCO_3) = 100.09 g/mol Step 3: Calculate the moles of CaCO_3. Moles of CaCO_3 = Mass of CaCO_3Molar mass of CaCO_3 Moles of CaCO_3 = 0.80 g100.09 g/mol = 0.0079928... mol Step 4: Use the mole ratio from the balanced equation to find the moles of CO_2. The balanced equation is: CaCO_3(s) + 2HCl(aq) CaCl_2(aq) + CO_2(g) + H_2O(l) From the equation, 1 mole of CaCO_3 produces 1 mole of CO_2. Moles of CO_2 = Moles of CaCO_3 = 0.0079928... mol Step 5: Calculate the volume of CO_2 at STP. At STP, 1 mole of any gas occupies 22.4 dm^3. Volume of CO_2 = Moles of CO_2 × 22.4 dm^3/mol Volume of CO_2 = 0.0079928... mol × 22.4 dm^3/mol Volume of CO_2 = 0.179038... dm^3 Volume of CO_2 = 0.179 dm^3 Drop the next question! 📸