Transcript The Mole
Objectives: ◦ Today I will be able to: Apply the mole conversion factor to calculations relating to the quantity of atoms in a sample Calculate the quantity of atoms in my name by completing a lab Informal assessment – monitoring student interactions as they complete the practice Formal assessment – analyzing student responses to the practice and the exit ticket Common Core Connection ◦ Make sense of problems and persevere in solving them ◦ Reason abstractly and quantitatively ◦ Build strong content knowledge Evaluate: Warm-Up Explain: Intro to the Mole Notes Elaborate: Mole Practice Evaluate: Exit Ticket What makes an atom neutral? Why would an atom not be neutral? Define mass number Describe the overall structure of an atom Can an atom gain or lose electrons? If it can, what is it called? Today I will be able to: ◦ Apply the mole conversion factor to calculations relating to the quantity of atoms in a sample ◦ Calculate the quantity of atoms in my name by completing a lab Have a great afternoon Warm-Up Intro to the Mole Notes Mole Practice Exit Ticket Example ◦ Instead of counting eggs individually we can count the number of dozens ◦ 1 dozen = 12 eggs OR 12 eggs = 1 dozen If a baker buys 6 dozen eggs, how many eggs does he have? 6 dozen 1 x 12 eggs 1 dozen = 72 eggs Atoms are too small and too numerous to count so we needed to develop a constant value of atoms to make it more reasonable to work with. The Mole (Avogadro's Number) 6.02 x 1023 602,000,000,000,000,000,000,000 If you took a mole of dollar bills and placed them next to each other around the circumference of the earth, they would go around the earth how many times? 2.34 x 1015 That’s Huge! Particles = Atoms, Molecules, Formula Units We will use this when we get to the gas law unit How many formula units of AgCl are in 2 moles of AgCl? How many Mg atoms are in 0.5 moles of Mg? Atomic mass is based on the mass of one mole of an element or compound ◦ 1 mole = atomic mass unit of an element or compound in grams (molar mass) Example: Carbon 1 mol of carbon = 12 grams carbon 12 grams of carbon has 6.02 x 1023 atoms of carbon What is the mass of one mole of Chlorine? ◦ 35.45 grams of chlorine = 1 mole of chlorine ◦ 35.45 grams of chlorine has 6.02 x 1023 atoms This is the Molar Mass of an element It can be used as a conversion factor! 35.45 grams Cl 1 mole Cl OR 1 mole Cl 35.45 grams Cl The formula mass of the elements can be used to find the molar mass of a compound Example: Water (H2O) Element Number Mass (g/mol) H 2 1.01 O 1 16.0 Total mass of Water 18.0 18.0 grams of water = 1 mole of water 18.0 grams of water has 6.02 x 1023 molecules of water If there was 20.0 g of iron, how many moles in that amount? 20.0 g Fe 1 x 1 mol 56 g Fe = .357 mol Fe If you have 10.0 g of water, how many molecules in that amount? 10.0 g H2O 1 x 1 mol x 18 g H2O = 6.02 x 1023 molecules 1 mol 3.34 x 1023 molecules of H2O If you have 25.0 g of copper (II) sulfate, CuSO4, how many formula units are in that mass? 25.0 g CuSO4 1 1 mol x 160 g CuSO4 = x 6.02 x 1023 formula units 1 mol 9.41 x 1022 formula units of CuSO4 How many moles are in 6.02 x 1025 molecules?