Final answer:
Using the empirical formula CH₂O and multiplying each subscript by three, the molecular formula C₃H₆O₃ is obtained. For the compound with ions Al³+ and SO₄²-, the chemical formula is Al₂(SO₄)₃ or Al₂S₃O₁₂, used to calculate the formula mass by combining the atomic masses of each element according to its subscript.
Step-by-step explanation:
To propose a molecular formula consistent with the given information, we use the empirical formula CH₂O as a starting point, and use the knowledge that the molecular formula is a multiple of the empirical formula. The question states that the molecular formula is derived by multiplying each subscript in the empirical formula by three. Therefore, we multiply each element's subscript by three in the empirical formula CH₂O to get the molecular formula C₃H₆O₃.
The subject of this question is about combining ions in a compound, considering their charges and the ratio in which they combine. The specific example includes Al³+ and SO₄²- ions in a 2:3 ratio, which results in the chemical formula Al₂(SO₄)₃. To calculate the formula mass, the compound is often expressed in its simplest whole number ratio as Al₂S₃O₁₂. Each element's atomic mass is then multiplied by its corresponding subscript to find the total formula mass.