Question

Flourine reacts with sulfur to form a compound which has 25.2% sulfur by mass and a relative molecular mass of 254. determine the molecular for mula of this compound

Answer 1

The compound created by the reaction of fluorine with sulfur that has 25.2% sulfur by mass and a molar mass of 254 has the molecular formula S2F10.

Step-by-step explanation:

To determine the molecular formula of the compound formed by fluorine and sulfur, we will use the given mass percentage and molar mass. With 25.2% of the compound's mass corresponding to sulfur and a molar mass of 254, we can calculate the moles of sulfur in one mole of the compound.

Firstly, calculate the mass of sulfur in one mole of the compound:

• Mass of sulfur = 25.2% of 254 g/mol = 0.252 × 254 g/mol = 64.008 g/mol

Then, calculate the moles of sulfur using its molar mass (approximately 32 g/mol):

• Moles of sulfur = Mass of sulfur / Molar mass of S = 64.008 g/mol / 32 g/mol = 2

Since we have 2 moles of sulfur, the part of the molecular formula corresponding to sulfur is S2. To determine the fluorine part, subtract the mass of sulfur from the total molar mass and calculate the moles of fluorine:

• Mass of fluorine = 254 g/mol - 64.008 g/mol = 189.992 g/mol
• Moles of fluorine = Mass of fluorine / Molar mass of F (approximately 19 g/mol)
• Moles of fluorine = 189.992 g/mol / 19 g/mol ≈ 10

Since there are approximately 10 moles of fluorine, the formula for fluorine in the compound is F10 . Combining sulfur and fluorine parts, we get the molecular formula S2F10.