Section 2.9 page 144 Stoichiometry is the science of using balanced chemical equations to determine exact amounts of chemicals needed or produced in a chemical reaction.
Write the balance equation: Procedure for solving Stoichiometric problems Example: Propane, C3H8(g), is a gas that is commonly used in barbecues. Calculate the mass of oxygen that is needed to burn 15 g of propane. Write the balance equation: Write out the ratio. (represents the # of moles needed)
Propane, C3H8(g), is a gas that is commonly used in barbecues Propane, C3H8(g), is a gas that is commonly used in barbecues. Calculate the mass of oxygen that is needed to burn 15 g of propane. 3. Indicate the known substances mass 4. Convert known substances mass into moles (you need the known mass and the molar mass)
Propane, C3H8(g), is a gas that is commonly used in barbecues Propane, C3H8(g), is a gas that is commonly used in barbecues. Calculate the mass of oxygen that is needed to burn 15 g of propane 5. Set up a proportion of from the ratio of # mole required and # of moles calculated, from given substance and unknown. 6. Solve for moles of unknown substance by solving the proportion above
Propane, C3H8(g), is a gas that is commonly used in barbecues Propane, C3H8(g), is a gas that is commonly used in barbecues. Calculate the mass of oxygen that is needed to burn 15 g of propane 7. Using the calculated unknown moles solve for grams using the # moles and Molar mass of unknown.
How many molecules of oxygen are produced from the decomposition of 12 g of water into its elements?
How many grams of oxygen are required to react with 9 How many grams of oxygen are required to react with 9.70 g of magnesium to form magnesium oxide?
Potassium chlorate breaks down to form potassium chloride and oxygen gas. What mass of potassium chloride must be decomposed to form 0.96 g of oxygen?
Assignment Page 148 questions 1 and 2 2 Al2O3 4 Al + 3 O2 2 K + 2 HCl 2 KCl + H2