An organic compound contains 49.3% carbon, 6.84% hydrogen and its vapors density is 73 Molecular formula of compound is
Correct answer: D. C4H10O2
- A. C3H5O2
- B. C6H10O4
- C. C3H10O2
- D. C4H10O2
Explanation
Here's how to solve the problem to find the molecular formula of the organic compound:Calculate the percentage of oxygen:% of oxygen = 100% - % of carbon - % of hydrogen = 100% - 49.3% - 6.84% = 43.86%Calculate the empirical formula:Assume 100g of the compound. This gives:49.3 g carbon (C)6.84 g hydrogen (H)43.86 g oxygen (O)Divide each mass by its respective atomic mass and express the results in the smallest whole-number ratio:C: 49.3 g / 12.01 g/mol ≈ 4.11 ≈ 4H: 6.84 g / 1.008 g/mol ≈ 6.79 ≈ 7O: 43.86 g / 16.00 g/mol ≈ 2.74 ≈ 2Therefore, the empirical formula is C₄H₇O₂Relate the empirical formula to the molecular formula:The vapor density of the compound is 73 g/mol.The empirical formula weight (sum of atomic masses in the empirical formula) is approximately 4(12) + 7(1) + 2(16) = 73 g/mol.This means the empirical formula is also the molecular formula, as the vapor density matches the empirical formula weight.Therefore, the molecular formula of the compound is C₄H₇O₂.
Last updated
About Fundamental Concepts of Chemistry
Mole calculations connect mass, number of particles and Avogadro's number, while balanced equations provide the mole ratios used in stoichiometry. Questions cover limiting and excess reactants, theoretical yield and percentage yield, including identifying which reactant is consumed first and comparing the actual product with the maximum possible product.
Practise Fundamental Concepts of Chemistry
894 free Fundamental Concepts of Chemistry MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Chemistry questions like this
Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
0.078 g of hydrocarbon occupies 22.4 ml of volume at 1 atm and 0˚C. The empirical formula of the hydrocarbon is CH. The molecular formula is:
0.36 moles of each aluminum and oxygen react with each other to produce aluminum oxide. The amount of product formed is
0.5 mole of H2O is formed when one gram of H2 react with how many gram of oxygen
0.5 mole of H2O is formed when one gram of H2 react with how many grams of oxygen?
0.5 moles of H₂O are formed when one gram of H₂ reacts with how many grams of oxygen?