Ask Question
11 September, 12:30

The compound XF3 containts 65% F (mass percentage). Mw (x) = ?

+3
Answers (1)
  1. 11 September, 13:43
    0
    The compound XF3 has a molar mass of 87.7 g/mol

    The element x has an atomic mass of 30.7 u

    This element can be P (phosphorus) and the compound will be PF3

    Explanation:

    Step 1: Data given

    Compound XF3 has a mass % of 65% F

    Step 2:

    The sample has 65% mass percent, this is the ratio of the element (F) it's mass compared to the mass of the compound.

    (Mass of F / mass of compound) * 100% = 65 %

    Step 3: Calculate molar mass of the compound

    F has an atomic mass of 19u (Since there are 3x F the atomic mass is 3*19 = 57 u)

    The compound XF3 has a molar mass of (X+57) g/mol

    ⇒ with X = the molar mass of compound x

    Mass % of F = 65% = (3*19g/mol) / (X+57) g/mol

    0.65 = (57 / (X+57))

    57 = 0.65 * (X+57)

    57 = 0.65X + 37.05

    19.95 = 0.65X

    X = 30.7 g/mol

    This means the atomic mass of the element x is 30.7 u

    To control this we can calculate the mass % of F

    ((3*18) / (30.7 + 3*18)) * 100% = 65%

    The compound XF3 has a molar mass of 87.7 g/mol

    The element x has an atomic mass of 30.7 u

    This element can be P (phosphorus) and the compound will be PF3
Know the Answer?
Not Sure About the Answer?
Find an answer to your question ✅ “The compound XF3 containts 65% F (mass percentage). Mw (x) = ? ...” in 📘 Chemistry if you're in doubt about the correctness of the answers or there's no answer, then try to use the smart search and find answers to the similar questions.
Search for Other Answers