Chemistry – Mar 15, 2017 P3 Challenge – Determine the percent composition of Fe(NO3)3 Today’s Objective – Moles and Chemical formulas Get out Empirical Formula Worksheet for HMK check Agenda Hmk Review Moles and Chemical formulas Assignment: Chemical Formula Worksheet
Chemical formulas and Conversion factors Because the chemical formula indicates the number and ratio of atoms in a compound, conversion factors can be written to convert between moles of atoms and moles of compounds. Ex: 1 mole CO2 contains 1 mole of C and 2 mole of O Ex: How many moles of O are present in 3.25 mol of H3PO4?
Gram – mole calculations using the chemical formula Grams of X Moles of Y Grams of Y Moles of X Not Here!! Molar mass Chemical formula
Gram – mole –number of items problems Grams of X Moles of Y Grams of Y Moles of X Not Here!! Molar mass Chemical formula Number of X Number of Y 6.022x1023 Atomic scale Macroscopic scale
Gram – mole problems using the chemical formula Grams of CO2 Ex: Determine the number of moles in a 15.0 g sample of CO2. Ex: What mass does 1.25 moles of CO2 have? Molar mass 44.01 g/mol Moles of CO2
Gram – mole problems using the chemical formula Moles of CO2 Moles of C or O Ex: Determine the number of moles of C in 8.30 mole of CO2. Ex: Determine the number of moles of O in 0.592 mole of CO2.
Gram – mole problems using the chemical formula Grams of CO2 Ex: Determine the number of moles of C in 15.0 g of CO2. Ex: Determine the number of moles of O in 15.0 g of CO2 Molar mass 44.01 g/mol Moles of CO2 Chemical formula Moles of C or O
Gram – mole problems using the chemical formula Grams of CO2 Grams of C, O Molar mass 44.01 g/mol Molar mass 12.01 g/mol, 16.00 g/mol Chemical formula Moles of CO2 Moles of C, O Ex: Determine the number of grams of a)carbon and b)oxygen in 22.75 g of CO2.
Gram – mole – number problems using a chemical formula Grams of X How many copper atoms are present in a 1.688 gram sample of copper (I) oxide, Cu2O? Molar mass 143.09 g/mol Moles of X Chemical formula Moles of Y Macroscopic scale Atomic scale Number of Y
Gram – mole –number of items problems Grams of X Moles of Y Grams of Y Moles of X Not Here!! Molar mass Chemical formula Number of X Number of Y 6.022x1023 Atomic scale Macroscopic scale
Exit Slip - Homework Exit Slip: A) How many grams of silver are present in 23.5 g of silver nitrate? B) How many atoms of silver are present? What’s Due? (Pending assignments to complete.) Chemical Formula worksheet What’s Next? (How to prepare for the next day) Read p100-102, p224-232, 241 p246-247