Chemists make useful substances in the lab using recipes. Pharmaceutical Drugs Plastics/ Petroleum Products

Useful things made from Sand using chemical recipes Starting Materials Final Product

Stoichiometry Chemistry Recipes

Stoichiometry Stoichiometry is the study of the relationship between the amounts of reactants and products in a chemical reaction Stoichiometry provides RECIPES for chemical reactions.

Key Concept of Unit The Coefficients of the balanced chemical equation represent the reacting ratios of particles (MOLES) of reactants and products.

Stoichiometry Problem Set HW 6-1 1) 2 Mg + O2 → 2 MgO video link

HW 6-1 , Problem #2 2) 2 H2 + O2 → 2 H2O video link

HW 6-1, #3 N2 + 3 H2 → 2 NH3

Stoichiometry Problem Set HW 7-1 4) 2 Mg + O2 → 2 MgO atoms molecules molecules A) 4 atoms + 2 molecules → B) 8 atoms + → 8 molecules C) + 10 molecules → 4 molecules 4 molecules 20 atoms 20 molecules

HW 6-1, #5 molecules molecules molecules A) + 15 molecules → 5. N2 + 3 H2 → 2 NH3 molecules molecules molecules A) + 15 molecules → B) 6.022 x 1023 + → molecules molecules molecules C) 1 mole + → 5 molecules 10 molecules 3(6.022 x 1023) 2(6.022 x 1023) 3 moles 2 moles

HW 6-1 , Problem #6 2) 2 H2 + O2 → 2 H2O 2 A) 2 moles + moles → moles B) moles + 4 moles → moles C) moles + moles → 10 moles 1 2 8 8 10 5

Quantities in a Balanced Chemical Equation

Use mole bridge for more complex ratios HW 7-1, #7A 4 NH3 + 7 O2 → 4 NO2 + 6 H2O ? Moles 10.0 moles 10.0 moles O2 ( ) 4 moles NH3 7 moles O2 Answer: 40/7 = 5.71 (3 SF, matches given)

Use mole bridge for more complex ratios HW 7-1, #7B 4 NH3 + 7 O2 → 4 NO2 + 6 H2O 11.5 moles ? Moles 11.5 moles NH3 ( ) 6 moles H2O 4 moles NH3 Answer: 17.25 = 17.3 (3 SF, matches given)

Use mole bridge for more complex ratios HW 7-1, #7C 4 NH3 + 7 O2 → 4 NO2 + 6 H2O ? Moles 8.6 moles 8.6 moles H2O ( ) 4 moles NO2 6 moles H2O Answer: 5.733 = 5.7 (2 SF, matches given)

Use mole bridge for more complex ratios HW 7-1, #7D 4 NH3 + 7 O2 → 4 NO2 + 6 H2O 9.2 moles ? Moles 9.2 moles O2 ( ) 6 moles H2 O 7 moles O2 Answer: 7.887 = 7.9 (2 SF, matches given)