Chemistry Forum

here are the problems---

A compound analyzes to be 37.5% C, 12.5% H, and 50.0% O. The molecular mass of the compound is 93.0. What is the molecular formula of the compound? (Type your answer using the format CH₄ for CH₄. Keep the elements in the order given.)




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40.
the composition of nicotine is 74.0% C, 8.7% H, and 17.3% N. Its molecular mass is 162. What is its molecular formula? (Type your answer using the format CH₄ for CH₄. Keep the elements in the order given.)



plz show how u did the problems

yon wrote:here are the problems---

A compound analyzes to be 37.5% C, 12.5% H, and 50.0% O. The molecular mass of the compound is 93.0. What is the molecular formula of the compound? (Type your answer using the format CH₄ for CH₄. Keep the elements in the order given.)

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40.
the composition of nicotine is 74.0% C, 8.7% H, and 17.3% N. Its molecular mass is 162. What is its molecular formula? (Type your answer using the format CH₄ for CH₄. Keep the elements in the order given.)

plz show how u did the problems

Just multiply molar mass by percent composition and divide by atomic weight of th atom.

For the second example:
C 162 * 74.0/100 /12 = 10
H 162 * 8.7/100/1.008 = 14
N 162 * 17.3/100/14 = 2
Thus the formula is C₁₀H₁₄N₂