Chapter 11: Empirical Formulas and Percent Composition by Michael McCuen https://padlet.com/mmccue6926/jp2vofpzgxej Overview of chapter 11 en-us 2017-11-27 15:07:44 UTC 2025-10-23 14:47:36 UTC hello@padlet.com Empirical Formulas mmccue6926 https://padlet.com/mmccue6926/jp2vofpzgxej/wish/210444817 Empirical Formulas show the smallest whole number ratio of the atoms in the compound.]]> 2017-11-27 15:13:26 UTC https://padlet.com/mmccue6926/jp2vofpzgxej/wish/210444817 Empirical Formula mmccue6926 https://padlet.com/mmccue6926/jp2vofpzgxej/wish/210445379 Empirical Formula: Percentage/ Molar Mass of Compound]]> 2017-11-27 15:14:10 UTC https://padlet.com/mmccue6926/jp2vofpzgxej/wish/210445379 Steps kfuent7970 https://padlet.com/mmccue6926/jp2vofpzgxej/wish/210445385 1. % composition (if = 100%) converts to mass.
2. Convert from mass to moles
3. Calculate simplest ratio.
(divide all # mol by the smallest # moles)
3 ½. If not all whole numbers, multiply all by a whole # to create whole #’s.
4. Use simplest ratio as subscripts.
]]> 2017-11-27 15:14:10 UTC https://padlet.com/mmccue6926/jp2vofpzgxej/wish/210445385 Example: Molecular Formula mmccue6926 https://padlet.com/mmccue6926/jp2vofpzgxej/wish/210449028 Calculate the molecular formula of a compound whose molar mass is 60 g/mol and Empirical Formula is CH4N.
1. Percent composition is 60
2. Molar Mass of CH4N = 30.04 grams
3. 60/30.04 =  2
4. CH4N x 2
5.Molecular Formula = C2H8N2

]]> 2017-11-27 15:19:39 UTC https://padlet.com/mmccue6926/jp2vofpzgxej/wish/210449028 Example: Empirical Formula mmccue6926 https://padlet.com/mmccue6926/jp2vofpzgxej/wish/210925212 A compound is found to contain 50.05 % sulfur and 49.95 % oxygen by weight. What is the empirical formula for this compound?
1. Change the percents to grams:
S -> 50.05 g 
O -> 49.95 g
2. Convert the masses to moles:
S -> 50.05 g / 32.066 g/mol = 1.5608 mol 
O -> 49.95 g / 16.00 g/mol = 3.1212 mol
3. Divide by the lowest, looking for the smallest whole-number:
S -> 1.5608 / 1.5608 = 1 
O -> 3.1212 / 1.5608 = 2
4. Write the empirical formula:
SO2
]]> 2017-11-28 14:50:24 UTC https://padlet.com/mmccue6926/jp2vofpzgxej/wish/210925212 Percent Composition mmccue6926 https://padlet.com/mmccue6926/jp2vofpzgxej/wish/211873915
  • Write the formula.
  • Use the formula to determine molar mass.
  • Use the molar mass to determine the mass percentage of each element.
    • If you have a compound that has the formula C2H5OH, first determine the mass of each element.

    • mass of C = (2 moles C / 1) * (12 g C / 1 mole) = 24 g C
    • mass of H = (6 moles H / 1) * (1 g H / 1 mole) = 6 g H
    When you are counting the number of hydrogens, don't forget to count the one at the end of the formula!

    • mass of O = (1 mole O / 1) * (16 g O / 1 mole) = 16 g O
      • Total mass = 24 g + 6 g + 16 g = 46 g
    Next, determine the percent of each element in the total compound.

    • C = (24 / 46) * 100% = 52%
    • H = (6 / 46) * 100% = 13%
    • O = (16 / 46) * 100% = 35%

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