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 = 24 + 32 + (4 × 16) = 24 + 32 + 64 = 120\, g/mol Molar mass of 7H₂O = 7 × ((2 × 1) + 16) = 7 × (2 + 16) = 7 × 18 = 126\, g/mol Molar mass of MgSO₄·7H₂O = 120 + 126 = 246\, g/mol Step 2: Calculate the total mass of oxygen in MgSO₄·7H₂O. Number of oxygen atoms in MgSO₄ = 4 Number of oxygen atoms in 7H₂O = 7 × 1 = 7 Total number of oxygen atoms = 4 + 7 = 11 Total mass of oxygen = 11 × 16\, g/mol = 176\, g/mol Step 3: Calculate the percentage by mass of oxygen. Percentage by mass of oxygen = Total mass of oxygenMolar mass of MgSO₄·7H₂O × 100\% 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: Compare with the given options. The calculated percentage is approximately 71.5\%. This matches option c. The final answer is c. 71.5%