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A compound contains 40% C, 6.7% H and 53.3% O by mass and has a molar mass of 180 g mol^-1. Its molecular formula is:

Answer: C₆H₁₂O₆.

A CH₂O
B C₂H₄O₂
C C₆H₁₂O₆
D C₃H₆O₃

Correct answer: C. C₆H₁₂O₆

Explanation: Mole ratio C:H:O = 40/12 : 6.7/1 : 53.3/16 = 3.33 : 6.7 : 3.33 = 1:2:1, giving empirical formula CH₂O (mass 30). 180/30 = 6, so molecular formula = C₆H₁₂O₆.

Mass connects to moles via molar mass, and moles connect to particle count via Avogadro's number or to gas volume via the 22.4 L/mol rule at STP.

Concept context

The mole is chemistry's counting unit. Learn to relate mass, volume, and number of particles using Avogadro's number and molar mass, the foundation of all stoichiometry and reaction calculations.

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A compound contains 40% C, 6.7% H and 53.3% O by mass and has a molar mass of 180 g mol-1. Its molecular formula is:

Concept context

More Some Basic Concepts of Chemistry questions

A compound contains 40% C, 6.7% H and 53.3% O by mass and has a molar mass of 180 g mol^-1. Its molecular formula is: