Percent Composition

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Category: Education
     
 

Presentation Description

The process for determining the elemental percent composition of a compound is described with examples.

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Percentage Composition: 

Percentage Composition Illustrates how much mass a given element contributes to the total mass of a compound Percentages help identify the formula of a compound

Solving Percentage Composition Problems: 

Solving Percentage Composition Problems Determine the total mass of each element present (atomic mass x subscript) Determine the total mass of the compound For each element, divide its total mass by the total mass of the compound Multiply by 100

What is the Percentage Composition of NaCl: 

What is the Percentage Composition of NaCl %Na %Cl Masses come from the atomic masses on the periodic table, rounded to 3 sig figs (first three digits of the mass). mass NaCl = 1(mass Na ) + 1(mass Cl ) = 23.0 + 35.5 = 58.5

What is the Percentage Composition of C2H5OH: 

What is the Percentage Composition of C 2 H 5 OH %C Masses come from the atomic masses on the periodic table, rounded to 3 sig figs (first three digits of the mass). mass C2H5OH = 2(mass C ) + 6(mass H ) + 1(mass O ) = 24.0 + 6.06 + 16.0 = 46.1 %H %O

How much Sodium (Na) could be recovered from 55.0 g of NaCl?: 

How much Sodium (Na) could be recovered from 55.0 g of NaCl? %Na = 39.3% %Cl = 60.7% mass Na = %Na (as a decimal) × mass NaCl = 0.393 × 55.0g = 19.7 g Na