7.1 Stoichiometry Objective 2 Chemistry

Essential Questions What is stoichiometry? How can you relate moles of two different compounds? How do you relate mass and liters of two different compounds?

Stoichiometry Study of quantitative (measurable) relationships in formulas of a reaction N2H4 + 2H2O2 → N2 +4 H2O Coefficients tells us how many individual particles, but it can also represent how many MOLES of a substance we have ALWAYS start with a complete BALANCED EQUATION!!

Molar Ratios Using coefficients we can relate the number of moles of compounds to one another with molar ratios Ex: 2 CuO + C → 2 Cu + CO2 Find the number of mol of CuO when you have 5.0 mol C. # mol want # = coefficient # mol given = 10 mol CuO

Mole to Mole Relationships NH4NO3 → N2O + 2H2O If we had 2 mol NH4NO3 How many moles N2O are produced? How many moles water are produced? 2KClO3  2K + Cl2 + 3O2 If you have 7.25 mol KClO3 How many moles Cl2? How many moles O2?

Mass to Mass conversion When given the mass of one substance and are asked to find the mass of another. There is not a direct relation between the mass of different substances. WHY? Mass Of Given (g) Moles Of Want Moles Of Given Mass Of Want (g) 1 mol given___ molar mass given molar mass want 1 mol want # mol want_ # mol given # = coefficient

Molar Conversion Answer the following questions for this equation Na2SO4 + 2KCl → 2NaCl + K2SO4 Find the number of mol of KCl for 7.00 mol of Na2SO4 Find the mass of NaCl for 2.5 mol of KCl Find the mol of K2SO4 for 125 g of KCl Find the mass of Na2SO4 given that there are 75 g of NaCl 14.0 mol KCl 146 g NaCl

Molar Conversion (cont) Answer the following questions for this equation CH4 + 2 O2 → CO2 + 2 H2O Find the number of mol of CO2 for 200. g of O2 Find the mass of CH4 for 5.0 mol of H2O Find the mass of O2 for 100. g of CH4

Mass to Volume Problems Mass Of Given (g) Moles Of want Moles Of Given Volume Of Want (L) 22.4 L want 1 mol want 1 mol given___ molar mass given # mol want_ # mol given # = coefficient

Practice Problems Balance the following equation and use it to answer the questions NaHCO3 → Na2O + H2O + CO2 If you have 3.3 mol Na2O how many liters of H2O vapor did you produce? If you have 4.0g of NaHCO3 what volume of CO2 at STP will be produced? If you have 36.9 g H2O what volume of CO2 did you produce?

Volume to Volume Problems Volume Of Given (L) Moles Of Want Moles Of Given Volume Of Want (L) 22.4 L want 1 mol want 1 mol given___ 22.4 L given # mol want_ # mol given # = coefficient

Answer the questions according to the following equation Practice Problems Answer the questions according to the following equation H2 + Cl2 → HCl 0.38 L of H2 reacts to form what volume of HCl gas? If you have 2.7 L of HCl how many liters of H2 do you have?

Essential Questions What is stoichiometry? How can you relate moles of two different compounds? How do you relate mass and liters of two different compounds?

7.1 Tracked Assignment P 379-380 #40-42, 44 (not b), 49