Final answer:
The mass of 0.432 moles of C₈H₉O₄ is 73.0 g, which is calculated by first finding the molar mass of C₈H₉O₄ (169.152 g/mol) and then multiplying it by the number of moles (0.432 moles).
Step-by-step explanation:
To find the mass of 0.432 moles of C₈H₉O₄, we first need to determine the molar mass of the compound C₈H₉O₄. This can be calculated by adding the atomic masses of all the atoms in the formula: (8 × atomic mass of carbon) + (9 × atomic mass of hydrogen) + (4 × atomic mass of oxygen). Using the periodic table, we find that the atomic mass for carbon (C) is approximately 12.01 g/mol, for hydrogen (H) is about 1.008 g/mol, and for oxygen (O) is roundly 16.00 g/mol. Thus, the molar mass of C₈H₉O₄ is (8 × 12.01) + (9 × 1.008) + (4 × 16.00) = 96.08 + 9.072 + 64.00 = 169.152 g/mol.
With the molar mass calculated, we can now find the mass of 0.432 moles of C₈H₉O₄ by multiplying the moles by the molar mass: 0.432 moles × 169.152 g/mol = 73.075584 g. Thus, the correct answer is 73.0 g when rounded to three significant figures.