Question

Which of the following is a quantity necessary to determine the molecular formula of a compound?

• A. Boiling point
• B. Rate of reaction
• C. Molecular mass
• D. Molarity (moles per litre)
• E. Density

Answer 1

The correct option is C Molecular mass

Molecular mass is a quantity necessary to determine the molecular formula of a compound.
From elemental analysis, we can determine the percentage composition of various elements present in the sample. From percent composition, we can calculate the empirical formula. But to convert empirical formula into molecular formula, we need molecular mass. The ratio of the molecular mass to the empirical formula mass gives the number of empirical formula units present in one molecular formula unit.