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
Step 1: Calculate the molar mass of MgSO₄·7H₂O. Molar mass of Mg = 24\, g/mol Molar mass of S = 32\, g/mol Molar mass of O = 16\, g/mol Molar mass of H = 1\, g/mol Molar mass of MgSO₄ is: 24 + 32 + (4 × 16) = 24 + 32 + 64 = 120\, g/mol Molar mass of 7H₂O is: 7 × ((2 × 1) + 16) = 7 × (2 + 16) = 7 × 18 = 126\, g/mol Molar mass of MgSO₄·7H₂O is: 120 + 126 = 246\, g/mol Step 2: Calculate the total mass of oxygen in one mole of MgSO₄·7H₂O. The MgSO₄ part contains 4 oxygen atoms. The 7H₂O part contains 7 × 1 = 7 oxygen atoms. Total number of oxygen atoms = 4 + 7 = 11 Total mass of oxygen in one mole of MgSO₄·7H₂O is: 11 × 16\, g/mol = 176\, g/mol Step 3: Calculate the percentage by mass of oxygen. The percentage by mass of oxygen is given by the formula: Percentage by mass of oxygen = Total mass of oxygenMolar mass of MgSO₄·7H₂O × 100\% Substitute the calculated values: Percentage by mass of oxygen = 176\, g/mol246\, g/mol × 100\% Percentage by mass of oxygen ≈ 0.715447 × 100\% Percentage by mass of oxygen ≈ 71.54\% Step 4: Select the correct option. The calculated percentage is approximately 71.5\%. This matches option c. The final answer is c. 71.5%