1 / 9

10-3: Empirical and Molecular Formulas

10-3: Empirical and Molecular Formulas. Percentage Composition. The mass of each element in a compound, compared to the mass of the entire compound (multiplied by 100) Tells you the percent of the mass made up by each element in the compound. How to calculate % comp:.

mari-solis
Download Presentation

10-3: Empirical and Molecular Formulas

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. 10-3: Empirical and Molecular Formulas

  2. Percentage Composition • The mass of each element in a compound, compared to the mass of the entire compound (multiplied by 100) • Tells you the percent of the mass made up by each element in the compound.

  3. How to calculate % comp: • (grams of X)/(total grams) x 100% • Complete sample problem #7 on pg 334 • Complete practice problem #14 on pg 334

  4. Empirical Formula • The smallest whole number ratio of the atoms of the elements in a compound • Remember glucose? • What is its molecular formula? • What is its empirical formula?

  5. Calculating Empirical Formula • 1) If given as percents, read them as grams (accurate if a 100 g sample) • 2) Convert each gram amount to moles • 3) Find the smallest whole number ratio by dividing each mole amount by the smallest number. Round as appropriate. • 4) Use that ratio to write the empirical formula

  6. Sample Problem #8 (pg 36)

  7. Molecular Formula • Gives the actual number of atoms of each element in a molecular compound. • Is a whole number multiple of the empirical formula.

  8. Finding the Molecular Formula • You will be given the molar mass of the molecular formula in the question. • Find the empirical formula. • Find the molar mass of the empirical formula. • Divide molecular formula mass by empirical formula mass. • This is the whole number multiple that you should multiply the empirical formula by.

  9. Practice problem #18 (pg 339) • Sample problem 9 (pg 338)

More Related