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    Density and Number of Atoms

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    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    The Density is 7.87g/cm^3 , and the average mass for a single iron atom is 9.28*10^-23g .
    How many iron atoms are present in an iron bar whose dimensions are 2.00 cm * 3.00 cm * 8.00 cm ?

    © BrainMass Inc. brainmass.com December 24, 2021, 4:47 pm ad1c9bdddf
    https://brainmass.com/chemistry/stoichiometry/density-number-atoms-7975

    SOLUTION This solution is FREE courtesy of BrainMass!

    We have

    Mass/Volume = Density

    The volume of the iron bar is V = 2 * 3 * 8 cm^3

    V = 48 cm^3

    Since the density of iron is given to be 7.87g/cm^3 we can calculate the mass of the iron bar as,

    mass = density * volume = 48 * 7.87 = 377.76 g

    This is the total mass of all the iron atoms in the bar. But each iron atom has a mass, m = 9.28 * 10^-23g

    We have 377.76g as the mass of N atoms in the bar

    ie, N*m = 377.76

    Now, N = 377.76/9.28 * 10^-23 = 40.7*10^23

    The number of iron atoms present in the bar is 40.7*10^23 (ans)

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    © BrainMass Inc. brainmass.com December 24, 2021, 4:47 pm ad1c9bdddf>
    https://brainmass.com/chemistry/stoichiometry/density-number-atoms-7975

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