PPT-The Mole Concept Molar Mass, Conversion Problems, Percentage Composition, Empirical Formulas,

The Mole Chemists counting number amount of a substance 1 mole is equal to 6022 x 10 23 atoms or particles or molecules Avogadros number There are always 6022 x 10 23 particles in . Week 22 Chemistry. Warm Up: . 3. Minutes. A certain bag of M&M’s has 8 blue candies, 7 red candies, 4 green candies, and 6 yellow candies. What percentage of the bag is blue M&M’s? . Record your Learning . Q: how long would it take to spend a mole of $1 coins if they were being spent at a rate of 1 billion per second?. Background: atomic masses. Look at the “atomic masses” on the periodic table. What do these represent?. Chemistry GT 3/20/15. Drill. Calculate the percent composition of Na. 2. SO. 4. .. HW: Molecular Formula WS (pg. 4). MM. =142.05 . g. /mol. 32.37% Na, 22.58% S, 45.05% O. Chem. Joke of the Day. The photon checked into a hotel. What did it say when the bellhop asked for its bag?. Molecular Formulas. Let’s use those mole conversions!. Empirical formula . tells you the lowest ratio of atoms within a molecule. Molecular formula . tells you the actual ratio of atoms within a molecule. The Mole. mole. (mol)- SI Unit for the amount of a substance that contains as many particles as there are atoms in exactly 12g of carbon-12.. A unit of counting, like the dozen.. Avogadro’s Number. Percent Composition, . Empirical/ Molecular . Formula . Finishing Up Ch. 10. In 1811, Avogadro proposed a hypothesis:. Volumes of gases at the same temp and pressure have the same number of particles. Percent Composition. Percent . Composition – . the . percentage . by mass of . each . element in a . compound (*note: not the ratio of elements in the compound). Law of Definite Proportions . – compounds always contain the same proportions of elements by mass.. big. concepts of Chemistry.. The mole is a . counting. number, just like. 1 dozen = . 12. things . 1 score = . 20. things . 1 ream = . 500. things . 1 mole = . 6.022 x 10. 23. . things or . 1 mole of a substance is 6.02 x 10. 23. . representative particles. .. Avogadro’s number = . 6.02 x 10. 23. Avogadro determined the difference between atoms and particles.. Representative particle. Lowest whole # ratio . H. 2. O. 2. (hydrogen peroxide) is it a empirical Formula?. No, you can reduce it to HO . . H. 2. O. 2 . is the molecular formula. Molecular formula shows the way the molecule is actually found in nature.. Determining Molecular Formulas. Calculate the molecular formula of a compound whose molar mass is 60.0 g/mol and has an empirical formula of CH4N.. What you need:. Empirical Formula. Molar Mass. Calculate the molar mass of the empirical formula. The Mole in Chemistry . Not this!!. Not this!!!. The Mole. The mole is a counting unit. 1 pair = 2. 1 dozen = 12. 1 mole = 6.022 x 10. 23. atoms. This number is known as Avogadro’s number after Italian chemist . Percent Composition. ~percent by mass of atoms present in a compound. = (mass of atom). . (total molar mass) x 100. water is . 88.81 . % Oxygen and . 11.19 . % Hydrogen. O- 16.00/18.016 x 100 = . 88.81 . First lesson of our next unit: U7 Stoichiometry . P3 Challenge – . Determine the number and kinds atoms for the chemical formula Al. 2. (SO. 4. ). 3. Today’s Objective –. Moles and particles. Assignment: .