ap chemistry

posted by .

18. Answer the following question that relate to the analysis of chemical compounds.
(a) A compound containing the elements C, H, N, and O is analyzed. When a 1.2359g sample is burned in excess oxygen, 2.241g of CO2(g) is formed. The combustion analysis also showed that the sample contained 0.048g of H.
(i) Determine the mass, in grams, of C in the 1.2359g sampleof the compound.
(ii) When the compound is analyzed for N content only, the mass percent of N is found to be 28.84%. Determine the mass, in grams, of N, in the original 1.2359g sample of the compound.
(iii) Determine the mass, in grams, of O in the original 1.2359g sample of the compound.
(iv) Determine the empirical formula of the compound.

  • ap chemistry -

    (I)
    2.241 g CO2 x (1 mol CO2/molar mass CO2) x (atomic mass C/1 mol C) = g carbon.

    (II)
    1.2359 g sample x 0.2884 = g nitrogen.

    (III)
    1.2359 g sample - g C - g N -g H = grams O.

    (IV)
    Convert g C to percent C.
    Convert g N to percent N.
    Convert g H to percent H.
    Convert g O to percent O.

    Take a 100 g sample which will give you the grams of C, H, O, and N equal to the percents of each.
    Convert g C, H, O, and N to mols by dividing by the atomic mass of C, H, O, and N respectively.
    Convert to the ratio of small whole numbers. The easiest way to do this is to divide the smallest number of mols by itself (which gives it a value of 1.000). Divide all the other mole values by the same small number, then take the ratio of those whole numbers.
    Post your work if you get stuck. Check my thinking. Check my work.

  • ap chemistry -

    thanks so much for your help!

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. chemistry

    one moles of a compound containing only carbon, hydrogen, and nitrogen was burned in the presence of excess oxygen to give 264g of CO2, 63 g of H20, and 46 g of NO2. Calculate the molecular formula of the compound.
  2. Chemistry

    A 2.52g sample of a compound containing only carbon, hydrogen, nitrogen, oxygen, and sulfur was burned in excess O to yield 4.36g of CO2 and 0.892g of H20. Another sample of the same compound of mass 4.14g, yielded g of SO3. A third …
  3. Chemistry

    Consider the following reaction: CH4 +2O2 -> CO2 + 2H2O. Delta H = -891 kJ Calculate the enthalpy change for each of the following cases: a. 1.00 g methane is burned in excess oxygen b. 1.00 x 10^3 L methane gas at 740. torr and …
  4. Chemistry

    A 0.100g sample of a compound containing C, H, and O is burned oxygen producing 0.1783 g of CO2 and 0.0734 g of H2O. Determine the empirical formula of the compound.
  5. Cemistry

    When a 0.952 g sample of an organic compound containing C, H,and O is burned completely in oxygen, 1.35 g of CO2 and0.826 g of H2O are produced. What is the empiricalformula of the compound?
  6. Chemistry

    a compound was analyzed and found to contain C,H,N,O, and Cl. When o.150g sample of this compound was burned, it produced 0.138 g of CO2 and 0.0566 g of H2O. All of the Nitrogen in another sample of mass 0.200 g was converted to 0.0238 …
  7. chemistry

    I got C_4 H_3 O_8 for this question but I'd like someone to check my answer, please. A 1.012 g sample of a compound containing C, H, and O was burned to produce 2.145 g CO2 and 0.3293 g H2O. Calculate the empirical formula of the compound
  8. Chemistry

    A compound containing only carbon, hydrogen and oxygen is subjected to elemental analysis. Upon complete combustion, a .1804g sample of the compound produced .3051g of CO2 and .1249g of H2O. What is the empirical formula of the compound?
  9. chemistry

    a 2.52-g sample of a compound containing only carbon, hydrogen, nitrogen, oxygen, and sulfur was burned in excess O to yield 4.23 g of CO2 and 1.01 g of H2O as the only carbon and hydrogen containing products respectively. Another …
  10. Chemistry

    A 2.20 g-sample of a compound containing carbon, hydrogen, and oxygen is burned and it produces 4.61 g CO2 and 0.94 g H2O. What is the empirical formula of this compound?

More Similar Questions