Apiece of iron is pound containing a compound containing 72.3% of iron and 27.7% oxygen with molecular mass of 231.4g mol. what is the molecular formula of compound?


  • Réponse publiée par: kateclaire

    Extensive properties, such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the substance present. Physical properties can be measured without changing a substance's chemical identity.


  • Réponse publiée par: hajuyanadoy


    What is the percentage of hydrogen in propanoic acid?

    Select one: a. 11.01 b. 6.81 c. 18.56 d. 8.16


    [First step]  Identify the compound:  

    The propanoic acid compound has the following molecular formula


    [Second step]  Identify molar mass of propanoic acid MM_{CH_3CH_2COOH} :

    molecular weight of the element in the compound = number of elements (n) *  molecular weight

    C = 3*(12.0107u) = 36.0321 u

    H = 6*(1.00794u) = 6.04764 u

    O = 2*(15.999u) = 31.998 u


    MM_{CH_3CH_2COOH} = 36.0321+6.04764+31.998

    MM_{CH_3CH_2COOH} = 74.07774

    \boxed{MM_{CH_3CH_2COOH} \approx 74.08\:g/mol}

    [Third step] Now, we apply the data to the percentage composition formula of an element, let us see:

    Percent\:composition\:of\:an\:element = \dfrac{n*molar\:mass\:of\:element}{mass\:of\:compound}*100\%

    Percent\:composition\:of\:an\:element = \dfrac{6*1.00794}{74.08}*100\%

    Percent\:composition\:of\:an\:element = \dfrac{6.04764}{74.08}*100\%

    Percent\:composition\:of\:an\:element \approx 0.0816*100\%

    \boxed{\boxed{Percent\:composition\:of\:an\:element \approx 8.16\:\%}}\end{array}}\qquad\checkmark

    d. 8.16

    the percentage of hydrogen in propanoic acid is 8.16 %


    I Hope this helps, greetings ... Dexteright02! =)

  • Réponse publiée par: rhaineandreirefuerzo


    There are three rules in order to determine how many significant figures a certain number has,

    A non-zero digit or number is always significant. Zeros positioned between a significant digit is significant. Zeros after a decimal point are significant.

    Therefore, following these rules we can finally answer your questions.

    For 10.300, we can conclude that this digit has 5 signicant figures.

    The zero between 1 and 3 is significant according to our rule number 2. Moreover, the trailing zeros or the zeros after the decimal point are significant according to rule number 3.

    Then, we proceed to the next digit which is 0.3.

    Two rules apply to this digit, the first and the third one. Because the zero is before the decimal point, we can conclude that the zero is not significant.

    Lastly, we have 0.3000.

    Again, the first and third rule applies to this digit. Therefore, we have 4 significant number.

    When answering these kind of questions, it is always helpful to remember the three rules I mentioned earlier.

  • Réponse publiée par: abyzwlye
    It has 4 colors red orange yellow light orange
Connaissez-vous la bonne réponse?
Apiece of iron is pound containing a compound containing 72.3% of iron and 27.7% oxygen with molecul...