WU 1/11 Balance: C12H22O11 (s) + O2 (g) -> CO2 (g) + H2O (g) To convert from moles to mass, which conversion fraction do you use? (check mole calculator) How many moles are present in 25.0 g of Cu(NO3)2 Translate the equation in Q1 (sugar)

12-1 Stoichiometry Asks how much or how many Stoicheion- Greek word for element Metron- Greek word for measure Uses chemical equations to determine “how much” (mass) of a product/ reactant to expect.

12-1 Stoichiometry Coined by Jeremias Richter, a German chemist in the 1790’s. He believed that he could prove the existence of God through chemistry and chemical laws.

Stoichiometry in Real Life SMORES Write down the ingredients and their amounts for making a smore. Write this as a chemical equation (remember coeffiecients) If 4 graham crackers are available with excess of everything else, how many smores will be made?

12-2 Stoichiometry in Chemistry Balance: CH4 + O2  CO2 + H2O The coefficients represent moles. Substances react in whole number ratios. Translate your balanced reaction into words, and include the molar amounts.

12-2 Mole Ratios Mole ratio: a ratio comparing two coefficients in a balanced chemical equation. Write all possible mole ratios for the reaction of methane bubbles. (include all pertinent information)

12-2 Using Mole Ratios EX: If 1 mole of methane reacts, how many moles of water are formed? YOU: If 3 moles of oxygen react, how many moles of carbon dioxide will form?

Practice: Magnesium reacts with oxygen gas to produce magnesium oxide. Balance the chemical equation If 3.5 moles of oxygen react, how many moles of magnesium oxide form? If 4 moles of magnesium oxide are formed, how many moles of magnesium were used?