Step 1 1 Molar mass of Na multiply by the subscript of Na in Na 2 2 Mass Na per mole Na 2 molar mass Na g Na 1 mol Na ratio of mol Na per mol Na 2 from formula 2 mol Na g Na 1 mol Na2 1 mol Na 2 Holt Chem File: Problem-Solving Workbook 75 Percentage Composition Step 2 2 Mass Na per mole Na 2 multiply by the inverse of the molar mass of Na 2 and multiply by 100 Percentage Na in Na 2 from Step 1 g Na 1 molar mass Na 2 1 mol Na percentage Na in Na2 1 mol Na g Na2 Now you can combine Step 1 and Step 2 into one calculation.
combining Steps 1 and g Na 2 mol Na 1 mol Na 2 CO 100 percentage Na in Na 2 1 mol Na 1 mol Na g Na 2 Finally, determine the percentage of carbon and oxygen in Na 2 by repeating the calculation above with each of those elements. Determine the percentage composition of each of the following compounds: a.
Your supervisor gives you a bottle containing a white crystalline compound and asks you to determine its identity.
Several unlabeled drums of this substance have been discovered in a warehouse, and no one knows what it is.
The most common types of problems with percent: Find P percent of A B is P percent of what?
Skills Worksheet Problem Solving Percentage Composition Suppose you are working in an industrial laboratory.
Before you report your conclusion to your boss, you decide to check a reference book to see if there are any other compounds that contain only the elements sodium, carbon, and oxygen.
You discover that there is another compound, sodium oxalate, which has the formula Na 2 C 2 O 4.
Fortunately, you can determine not only which elements are in the compound, but also how much of each element is present.
As you have learned, every compound has a definite composition.