1 / 11

Percent Composition

Percent Composition. Percent Composition. The gram formula mass of a compound represents the TOTAL MASS of the compound What percent of the total mass is each element in the compound? Remember: percent means “out of 100”. For example…. This cup contains a total mass of

johnv
Télécharger la présentation

Percent Composition

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Percent Composition

  2. Percent Composition The gram formula mass of a compound represents the TOTAL MASS of the compound What percent of the total mass is each element in the compound? Remember: percent means “out of 100”

  3. For example…. This cup contains a total mass of 100 g of liquid. 75 g are “coffee” and 25 g are “cream”. What is the percent composition of the liquid in the cup? 75g coffee x 100 = 75% coffee 100g total 25g cream x 100 = 25% cream 100g total

  4. What is the percent composition of potassium chlorate? Formula = KClO3 Gram Formula Mass : K = 1 x 39 = 39 Cl = 1 x 35.5 = 35.5 O = 16 x 3 = 48 +______ 122.5 g What percent of the total mass (122.5 g) is each of the elements (K, Cl, and O) in the compound?

  5. 39 g x 100 = 31.8 % 122.5 g K = 39 g 35.5 g x 100 = 29.0 % 122.5 g Cl = 35.5 g 48 g x 100 = 39.2 % 122.5 g O3 = 48 g + ________ 100 %

  6. Percent composition formula is in Table T (back page) mass of part x 100 mass of whole

  7. You try it! What is the percent composition of MgBr2? Mg = 24 g x 1 = 24 g Br = 80 g x 2 = 160g +_____ 184 g Mass of whole % Mg 24 g (mass of part) x 100 = 13.0 % 184 g % Br 160 g x 100 = 87.0 % 184 g

  8. % Composition and Hydrates Same as other compounds, except treat the “water” as a part: What is the % composition of water in the hydrated compound Na2CO3• 10 H2O

  9. Na2CO3• 10 H2O Total mass (GFM) = 286 g Mass of water (the “part”) = 10 x 18g = 180 g % composition of water = 180 g x 100 = 62.9 % water 286 g

  10. You try it! What is the percent composition of water and calcium sulfate in the hydrated compound CaSO4 • 2H2O 21 % water 79 % calcium sulfate

More Related