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anonymous

  • one year ago

A compound contains 15.81%C, 0.66%H and 83.53% I. If its molar mass is 455.7g/mol, what is its molecular formula

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  1. owlet
    • one year ago
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    I think you should find the empirical formula first by converting each atom into moles. % of atom = mass of atom in the compound mass of atom x (1/molar mass of atom) = # number of moles then divide each mole by the smallest mole number.. This will give you the pseudo chemical formula of the compound. After you finish this part, I'll tell you what's the next step.

  2. owlet
    • one year ago
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    15.81 g of Carbon convert it to moles. you may need to use the periodic table. Molar mass of carbon is approx 12 g/mol 15.81 g C (1 mol C /12 g C) g will get cancelled, so you'll left with 15.81/12 mol of C Use calc to simplify Do the same thing for O, and H

  3. anonymous
    • one year ago
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    for the empirical formula i ended up getting C2HI Now what? @owlet

  4. anonymous
    • one year ago
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    what did you get for the oxygen?

  5. anonymous
    • one year ago
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    where am i geting O from isnt it supposed to be I? If so i got the following: C=1.3175 H=0.654761904 I=0.65823483 @owlet @Data_LG2

  6. anonymous
    • one year ago
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    Oh sorry lol, I thought it is oxygen So you are right. Empirical formula would be \(\sf C_2HI\) The last step you have to do it to find the molar mass of this compound using the empirical formula that you found. Then, divide the given molar mass by the molar mass you calculated from the empirical formula. The quotient will serve as the factor to gain the molecular formula.

  7. anonymous
    • one year ago
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    C = 2 x 12 H = 1 I = 127 add these, what will you get?

  8. anonymous
    • one year ago
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    I got 152 @Data_LG2

  9. anonymous
    • one year ago
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    yes, then divide the given molar mass(455.7) to that calculated molar mass(152)

  10. anonymous
    • one year ago
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    2.998026316 @Data_LG2

  11. anonymous
    • one year ago
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    yes so 3 will be the factor|dw:1443060372787:dw|

  12. anonymous
    • one year ago
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    C6H3I3 @Data_LG2

  13. anonymous
    • one year ago
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    yes

  14. anonymous
    • one year ago
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    Just a recap from @owlet 's instructions to mine. For future reference: 1. Assume a 100g sample: % of atom = mass of atom in the compound 2. Convert masses to moles: given mass (1/molar mass) 3. Calculate mole ratio: Dividing the smallest mole from step 2 4. Write the empirical formula 5. Calculate the Molar Mass of the compound from the empirical chemical formula 6. Divide the given molar mass by the molar mass calculated from step 5 7. The quotient will be the factor, which will be used to write the molecular mass :)

  15. anonymous
    • one year ago
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    **molecular formula

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