Question

A major ile dye manufacturer developed a new yellow dye. The dye has a percent composition of 75.95% C, 17.72% N, and 6.33% H by mass with a molar mass of about 240 g/mol. Determine the molecular formula of the dye.

a) C₁₂H₆N₂
b) C₁₀H₄N₂
c) C₁₄H₈N₂
d) C₁₆H₁0N₂

Answer 1

To determine the molecular formula of the dye, you need to calculate the empirical formula and compare it to the molar mass of the dye.

Step-by-step explanation:

To determine the molecular formula of the dye, we first need to calculate the empirical formula. The percent composition tells us the ratios of the elements in the dye.

We convert the percentages to grams and then divide by their molar masses to get the moles of each element. Then we divide the moles by the smallest number of moles to get the mole ratios.

In this case, the empirical formula is C₅H₇N. To find the molecular formula, we need to compare the molar mass of the empirical formula to the molar mass of the dye.

We divide the molar mass of the dye by the molar mass of the empirical formula to get the factor by which we need to multiply the empirical formula. The molecular formula of the dye is C₁₀H₁₄N₂.