1 / 11

10.2

10.2. Moles & Volume. Moles and mass. Equation to convert between mass (g) and moles ( mol ): REMEMBER: mass will be in g (grams) , not amu (atomic mass units) . Moles and gas i. Gas is represented with MOLAR VOLUME instead of mass. 1 mol of gas is 22.4 L

amil
Download Presentation

10.2

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. 10.2 Moles & Volume

  2. Moles and mass • Equation to convert between mass (g) and moles (mol): • REMEMBER: mass will be in g (grams), not amu (atomic mass units).

  3. Moles and gas i • Gas is represented with MOLAR VOLUME instead of mass. • 1 molof gas is 22.4 L • This volume is at a standard temperature and pressure (STP) • So really, we need to write this as: • 1 molof gas is 22.4 L at STP

  4. Moles and gas II • Equation to convert between volume OF A GAS (L) and moles (mol):

  5. Moles and density Remember that: If we know the DENSITY of a gas, we have an equation to relate that to mols:

  6. 10.3 Percent Composition and Chemical Formulas

  7. Percent composition This is the % by MASS. We can calculate this like we do any other percentage:

  8. % Composition form a chemical formula If we ONLY know the CHEMICAL FORMULA, then we can calculate the mass of each element in a mole of that compound. The sum of all the masses of the elements is the MOLAR MASS

  9. % comp as a conversion factor If we always know that 4 tires are on 1 car, I can calculate the number of tires in a parking lot based on the number of cars. I don’t have to count the number of tires individually. In the same manner, if I know 18g of H are always in 100g C3H8 (propane), then if I have a sample of 82.0g C3H8, I can know how many grams of H were in my sample.

  10. EMPIRICAL FORMULAS These are the smallest whole number ratios of the atoms in a compound.

  11. Molecular formulas • Some formulas have THE EXACT RATIO of atoms in them, but they have different molar masses. • For example: • Ethyne (C2H2) versus Benzene (C6H6) versus Styrene (C8H8) • The whole-number ratio is 1:1 between C and H, but the two molecules are different.

More Related