Problem: A compound whose empirical formula is XF3 consists of 65 % F by mass.What is the atomic mass of X?  Express your answer in grams per mole to two significant figures.

FREE Expert Solution

Mass % F:


% mass F=mass F in XF3molar mass XF3 ×100molar mass XF3 =mass F in XF3% mass F100

  • atomic mass of F = 19 g/mol

molar mass XF3 =3×19 gmol F% mass F100=57 gmol65100 = 87.69 g/mol


molar mass XF= atomic mass X + 3( atomic mass F)

96% (247 ratings)
View Complete Written Solution
Problem Details

A compound whose empirical formula is XF3 consists of 65 % F by mass.

What is the atomic mass of X?  Express your answer in grams per mole to two significant figures.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Mass Percent concept. You can view video lessons to learn Mass Percent. Or if you need more Mass Percent practice, you can also practice Mass Percent practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Bryant's class at USF.