1. Unit: Stoichiometry Using mole ratios and review of balancing chemical equations Day 1 - Notes

2. After today you will be able to… Calculate the number of moles of a substance that can be produced from their coefficients in the balanced chemical equation Review of the basics of how to balance a chemical equation

3. Stoichiometry: The study of quantities as it relates to chemical reactions. The word stoichiomety comes from the Greek words: stoicheion (meaning "element") metron (meaning "measure")

4. Balanced chemical equations can be interpreted many ways… 1N 2(g) + 3H 2(g)  2NH 3(g) molecules: NN HH +  HH HH N HH H N HH H

5. Balanced chemical equations can be interpreted many ways… mass: +  28.02g 6.06g 34.08g = Mass of reactants and products are always equal! 1N 2(g) + 3H 2(g)  2NH 3(g)

6. Balanced chemical equations can be interpreted many ways… moles: +  1 mol N 2 3 mol H 2 2 mol NH 3 This is the relationship we will focus on in this unit! 1N 2(g) + 3H 2(g)  2NH 3(g)

7. Mole-Mole Calculations The coefficients in the balanced equation represent the smallest whole number mole ratio between reactants and products.

8. Mole-Mole Calculations Examples of mole ratios for the reaction: 1N 2(g) + 3H 2(g)  2NH 3(g) 1 mol N 2 2 mol NH 3 3 mol H 2 1 mol N 2 2 mol NH 3 2 mol H 2

9. Mole-Mole Calculations Example: If 3.86 moles of potassium reacts completely with excess water, how many moles of hydrogen would be produced? potassium water  + potassium hydroxide + hydrogen hydrogen hydroxide __K + __ H(OH)  __ K(OH) + __ H 2 22 2 1 K: 3.86 mol K U: ? mol H 2 3.86 mol K 1 x 1 mol H 2 2 mol K = 1.93 mol H 2

10. Mole-Mole Calculations Example: How many moles of aluminum will react with 0.512 moles of hydrochloric acid? aluminumhydrochloric acid  + aluminum + hydrogen chloride hydrogen chloride __Al + __HCl  __ AlCl 3 + __ H 2 26 2 3 K: 0.512 mol HCl U: ? mol Al 0.512 mol HCl 1 x 2 mol Al 6 mol HCl = 0.171 mol Al

11. Questions? Complete WS 1 for HOMEWORK!