When 1 gram of sex hormone (contains C, H, and O) was burned in a combustion analysis, 1.5 grams of CO2 and 0.405 grams of H2O were obtained. The molar mass was found to be 352g/mol. What is the molecular formula for the sex hormone?

  1. 👍 0
  2. 👎 0
  3. 👁 236
  1. Convert 1.5 g CO2 to g C.
    Convert 0.405 g H2O to g H.
    Determine O by
    1.00 g sample- gC - gH = g O.

    Convert g each to moles.
    moles C = g/atomic mass C.
    moles H = g/atomic mass H.
    moles O = g/atomic mass O.

    Now find the ratio of the atoms to each other with the smallest number being 1.00. The easy way to do that is to divide the smallest number by itself; therefore, that number will be 1.00 and the other numbers will follow. Round to whole numbers (BUT don't round too much). If one of the numbers is further away than about 0.2 or so from a whole number, I would multiply the first set of numbers by 2, then 3, then 4, then 5, etc until all are reasonably close to whole numbers. That gives you the empirical formula.
    To find the molecular formula, divide 352/mass empirical formula and round that answer to a whole number. That will be n in the following:
    (CxHyOz)n where x,y,z are the subscripts in the empirical formula. Post your work if you need help through this. Be glad to help.

    1. 👍 0
    2. 👎 0
  2. okay,this is what i have so far:
    so is the chemical formula:
    O2 + CxHyOz --> CO2 + H2O ?

    CO2: 0.41 g of C
    1.09 g of O2
    H2O: 0.045 g of H2
    0.36 g of O

    Empirical Formula: CH2O -> n = 0.033 mol

    C: 0.033 mol x 12g/mol = 0.396 g of C
    H2: 0.033 mol x 2g/mol = 0.066 g of H2
    O: 0.033 mol x 16g/mol = 0.528 g of O

    is this right?

    1. 👍 0
    2. 👎 0
  3. .41 (I used 0.409 since I'm allowed three places) is correct.
    .045 g H is correct; not H2.
    Then 1 - 0.409 - 0.045 = 0.546 g Oxygen.

    Then 0.409/12 = ? moles C
    0.045/1 =? moles H
    0.546/16 = ? moles O.
    Then continue.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. General Chemistry I

    When a 0.432g sample of a mixture of volatile hydrocarbons is burned in a bomb calorimeter with heat capacity of 3046 J/C, the temperature rises by 7.82C. How much energy (in KJ) is released during combustion. **I got that

    asked by Ashley on October 31, 2012
  2. Biology

    What is the target organs for Luteinizing Hormone and the Follicle Stimulating Hormone?

    asked by Melanie on April 29, 2010
  3. More Chem

    Consider the combustion of propane. Delta H is -2221 kJ. Assume all heat is from combustion of propane. What mass of propane must be burned in order to furnish this amount of energy assuming the heat transfer process is 60%

    asked by Victor on April 8, 2017
  4. Chemistry

    Consider the combustion of propane: C3H8(g)+5O2(g) yields 3CO2(g) + 4H2O(l) delta H= -2221 kJ Assume that all of the heat comes from the combustion of propane. Calculate delta H in which 5.00g of propane is burned in excess oxygen

    asked by Shellby on November 13, 2011
  1. chemistry

    A 1.800 g sample of octane, C8H18, was burned in a bomb calorimeter whose total heat capacity is 11.66 kJ/°C. The temperature of the calorimeter plus contents increased from 21.12°C to 29.85°C. What is the heat of combustion

    asked by evgeny on January 31, 2013
  2. chemistry

    During the combustion of 5.00g of octane C8H18, 239.5 kcal is released. Write a balanced equation for the combustion reaction. Are reactants or products favored? What is the sign of change of heat for this reaction? how much

    asked by jennifer on June 7, 2015
  3. Chemistry

    C2H5OH(l) + 3 O2(g) -> 2 CO2(g) + 3 H2O(g) During an experiment 10.00 g of ethanol is completely burned in air to release CO2(g) and H2O(g) as shown in the equation above. During the combustion, 296.6 kJ of heat energy is

    asked by Anonymous on March 27, 2015
  4. Chemistry

    When 0.3212g of glucose was burned in bomb calorimeter of calorimeter constant 641J/K, the temperature rose by 7.943 K. Calculate a) the standard molar internal energy of combustion b) the standard enthalpy of combustion and c)

    asked by Nadira on May 4, 2010
  1. chemistry

    Methane (CH4) is the main component of natural gas. It is burned for fuel in a combustion reaction. The unbalanced combustion reaction for methane is shown below. CH4 + O2 CO2 + H2O + heat When the reaction is balanced, how many

    asked by Sarah on August 16, 2017
  2. physiology

    Match each term with the appropriate description. A. peptide hormone B. steroid hormone C. amino acid-derived hormone D. anterior pituitary E. hypothalamus F. posterior pituitary lipophobic molecule that interacts with receptors

    asked by lilianna on November 7, 2012
  3. chemistry

    Combustion analysis of 1.00g of the male sex hormone, testosterone, yields 2.90 g of CO2 and .875 g H2O. What are the mass percents of carbon, hydrogen, and oxygen in testosterone? How do I solve this? How many grams of C is in

    asked by Chris on October 16, 2006
  4. Chemistry

    1.) The the following reaction is: BaCO3 --> BaO + CO2 Decomposition reaction Single replacement reaction Combustion Reaction Synthesis Reaction Double replacement reaction 2.) When magnesium is burned in the presence of oxygen,

    asked by Clueless on February 5, 2018

You can view more similar questions or ask a new question.