Determine the molecular formula of a compound that contains 26.7%, 12.1%, and 61.2%, and has a molar mass of 812 g/mol.

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Chemistry

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24 December, 22:44

Determine the molecular formula of a compound that contains 26.7%, 12.1%, and 61.2%, and has a molar mass of 812 g/mol.

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Twiggy · Answer 1

Answer is: the molecular formula of a compound is P₇N₇Cl₁₄.

If we use 100 grams of substance:

ω (P) = 26.7% : 100% = 0.267.

m (P) = 0.267 · 100 g = 26.7 g.

n (P) = 26.7 g : 31 g/mol = 0.86 mol.

n (N) = 12.1 g : 14 g/mol = 0.86 mol.

n (Cl) = 61.2 : 35.45 g/mol = 1.72 mol.

n (P) : n (N) : n (Cl) = 0.86 mol : 0.86 mol : 1.72 mol / 0.86 mol.

n (P) : n (N) : n (Cl) = 1 : 1 : 2.

M (PₓNₓCl₂ₓ) = 812 g/mol.

M (PₓNₓCl₂ₓ) = 31x + 14x + 70.9x · g/mol.

812 g/mol = 115.9x · g/mol.

x = 7.