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Mountains into Molehills. Mass-Mole Conversions. Chem Catalyst. Arsenic, As, arsenic (III) oxide, As 2 O 3 , and arsenic (III) sulfide, As 2 S 3 , are all toxic because they contain arsenic. Which is more toxic, 1 mol of As or 1 mol of As 2 O 3 ? Explain your thinking.
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Mountains into Molehills Mass-Mole Conversions
Chem Catalyst • Arsenic, As, arsenic (III) oxide, As2O3, and arsenic (III) sulfide, As2S3, are all toxic because they contain arsenic. • Which is more toxic, 1 mol of As or 1 mol of As2O3? Explain your thinking. • Which is more toxic, 1 g of As2O3 or 1 g of As2S3? Explain.
Activity • Tape the questions to your left-hand page • Answer the questions on the right-hand page. • Tape tables onto the right hand page in the appropriate place in the question sequence.
Homework • Toxins Lesson 11: Mountains into Molehills • Pages 392-394 • Questions 3-8
Discussion • Why is it important to be able to convert back and forth between mass and number of moles? • Using Dimensional Analysis to convert: = = 6.02 x 1023 items 1 mole 1 mole 6.02 x 1023 items 1 mole X grams X grams 1 mole
Practice Using Dimensional Analysis • How many moles of As in a sample with a mass of 125 g? • What is the mass in grams of 3.0 moles of Mg? • How many moles of CaCl2 are in a sample with a mass of 10g? • What is the mass of a 0.16 mole sample of Cl2? • How many molecules are in 0.0583 moles of H2O? • How many molecules are in a 35 gram sample of H2O?
Gas Molar Volume • Can you measure the mass of a gas easily? • What is the volume of one mole of a gas? Check your Lesson 10, What’s in a Mole, table. • Do you think this is always true for every gas? • Standard temperature = 273 degrees Kelvin (what is this in Celsius?) • Standard pressure = 1 atmophere (atm) (= 14.7 lb/in2) • STP = 273 deg K and 1 atm • All gasses occupy 22.4 Liters at STP
Gas Conversions 22.4 Liters 1 mole 1 mole 22.4 Liters • What is the volume of 2.5 moles of oxygen gas (O2) at STP? • How many moles of CH4 gas is in 0.4 Liters at STP? • How many grams of N2 gas is in 6.8 Liters at STP? =
The Mole House • In the Mole House, in order to get to any other room, you must pass through the “Moles Room”.
Sample Problems • On whiteboard