Ask Question
30 March, 01:38

5.00 g of a certain Compound X, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 78./gmol, is burned completely in excess oxygen, and the mass of the products carefully measured, product mass:

carbon dioxide 16.93g

water 3.46g

Use this information to find the molecular formula of X.

+2
Answers (1)
  1. 30 March, 01:46
    0
    The molecular formula = C6H6

    Explanation:

    Step 1: Data given

    Mass of compound X = 5.00 grams

    Mass of products =

    CO2 = 16.39 grams

    H2O = 3.46 grams

    Molar mass CO2 = 44.01 g/mol

    Molar mass H2O = 18.02 g/mol

    Molar mass C = 12.01 g/mol

    Molar mass H = 1.01 g/mol

    Molar mass O = 16. 0g/mol

    Step 2: Calculate moles

    Moles = mass / molar mass

    Moles CO2 = 16.93 grams / 44.01 g/mol

    Moles CO2 = 0.385 moles

    Moles C = 1 * 0.385 = 0.385 moles

    Moles H2O = 3.46 grams / 18.02

    Moles H2O = 0.192 moles

    Moles H = 2 * 0.192 = 0.384 moles

    Step 3: Calculate mass

    Mass = moles * molar mass

    Mass C = 0.385 moles * 12.0 g/mol

    Mass C = 4.62 grams

    Mass H = 0.39 grams

    Mass O = 5.00 - 4.62 - 0.38 moles

    Mass O = 0 grams

    Step 4: Calculate mol ratio

    We divide by the smallest amount of moles

    C: 0.385 moles / 0.384 = 1

    H: 0.384 moles / 0.384 = 1

    The empirical formula is CH

    This molecular formula is 13 g/mol

    We have to multiply the empirical formula by n

    n = 78 g/mol / 13 g/mol

    n = 6

    The molecular formula = 6 * (CH) = C6H6
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “5.00 g of a certain Compound X, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 78./gmol, is ...” in 📗 Chemistry if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers