Chemical Equations & Reaction Stoichiometry
Chemical Equations Look at the information an equation provides: Reactants Yields Products
Chemical Equations Look at the information an equation provides: Reactants Yields Products 1 formula unit 3 molecules 2 atoms
Chemical Equations Look at the information an equation provides: Reactants Yields Products 1 formula unit 3 molecules 2 atoms 1 mole 3 moles 2 moles
Chemical Equations Look at the information an equation provides: Reactants Yields Products 1 formula unit 3 molecules 2 atoms 1 mole 3 moles 2 moles 159.7 g 84.0 g 111.7 g 132 g
Chemical Equations Law of Conservation of Matter There is no detectable change in quantity of matter in an ordinary chemical reaction. Balanced chemical equations must always include the same number of each kind of atom on both sides of the equation. This law was determined by Antoine Lavoisier.
Chemical Equations Propane,C3H8, burns in oxygen to give carbon dioxide and water.
Chemical Equations Propane,C3H8, burns in oxygen to give carbon dioxide and water.
Law of Conservation of Matter NH3 burns in oxygen to form NO & water
Law of Conservation of Matter NH3 burns in oxygen to form NO & water
Law of Conservation of Matter C7H16 burns in oxygen to form carbon dioxide and water.
Law of Conservation of Matter C7H16 burns in oxygen to form carbon dioxide and water.
Calculations Based on Chemical Equations Example 3-2: How many iron atoms can be produced by the reaction of 2.50 x 105 formula units of iron (III) oxide with excess carbon monoxide?
Calculations Based on Chemical Equations Example 3-2: How many iron atoms can be produced by the reaction of 2.50 x 105 formula units of iron (III) oxide with excess carbon monoxide?
Limiting Reactant Concept Example 3-7: Suppose a box contains 87 bolts, 110 washers, and 99 nuts. How many sets, each consisting of one bolt, two washers, and one nut, can you construct from the contents of one box?
Limiting Reactant Concept Example 3-7: Suppose a box contains 87 bolts, 110 washers, and 99 nuts. How many sets, each consisting of one bolt, two washers, and one nut, can you construct from the contents of one box? Can construct only 55 sets before running out of washers.
Limiting Reactant Concept Example 3-8: What is the maximum mass of sulfur dioxide that can be produced by the reaction of 95.6 g of carbon disulfide with 110. g of oxygen?
Limiting Reactant Concept Example 3-8: What is the maximum mass of sulfur dioxide that can be produced by the reaction of 95.6 g of carbon disulfide with 110. g of oxygen?
Limiting Reactant Concept Example 3-8: What is the maximum mass of sulfur dioxide that can be produced by the reaction of 95.6 g of carbon disulfide with 110. g of oxygen?
Percent Yields from Reactions Theoretical yield is calculated by assuming that the reaction goes to completion. Determined from the limiting reactant calculation. Actual yield is the amount of a specified pure product made in a given reaction. In the laboratory, this is the amount of product that is formed in your beaker, after it is purified and dried. Percent yield indicates how much of the product is obtained from a reaction.
Percent Yields from Reactions Example 3-9: A 10.0 g sample of ethanol, C2H5OH, was boiled with excess acetic acid, CH3COOH, to produce 14.8 g of ethyl acetate, CH3COOC2H5. What is the percent yield?
Percent Yields from Reactions Example 3-9: A 10.0 g sample of ethanol, C2H5OH, was boiled with excess acetic acid, CH3COOH, to produce 14.8 g of ethyl acetate, CH3COOC2H5. What is the percent yield? Theoretical Yield: Percent Yield
Sequential Reactions Example 3-10: Starting with 10.0 g of benzene (C6H6), calculate the theoretical yield of nitrobenzene (C6H5NO2) and of aniline (C6H5NH2).
Sequential Reactions Example 3-10: Starting with 10.0 g of benzene (C6H6), calculate the theoretical yield of nitrobenzene (C6H5NO2) and of aniline (C6H5NH2).
Sequential Reactions Example 3-10: Starting with 10.0 g of benzene (C6H6), calculate the theoretical yield of nitrobenzene (C6H5NO2) and of aniline (C6H5NH2).
Sequential Reactions Example 3-10: Starting with 10.0 g of benzene (C6H6), calculate the theoretical yield of nitrobenzene (C6H5NO2) and of aniline (C6H5NH2).
Sequential Reactions Example 3-10: If 6.7 g of aniline is prepared from 10.0 g of benzene, what is the percentage yield?
Sequential Reactions Example 3-10: If 6.7 g of aniline is prepared from 10.0 g of benzene, what is the percentage yield?
Concentration of Solutions Solution is a mixture of two or more substances dissolved in another. Solute is the substance present in the smaller amount. Solvent is the substance present in the larger amount. In aqueous solutions, the solvent is water. The concentration of a solution defines the amount of solute dissolved in the solvent. The amount of sugar in sweet tea can be defined by its concentration.
Concentrations of Solutions Common unit of concentration:
Concentrations of Solutions Example 3-15: Calculate the molarity of a solution that contains 12.5 g of sulfuric acid in 1.75 L of solution.
Concentrations of Solutions Example 3-15: Calculate the molarity of a solution that contains 12.5 g of sulfuric acid in 1.75 L of solution.
Concentrations of Solutions Example 3-16: Determine the mass of calcium nitrate required to prepare 3.50 L of a 0.800 M Ca(NO3)2 .
Concentrations of Solutions Example 3-16: Determine the mass of calcium nitrate required to prepare 3.50 L of 0.800 M Ca(NO3)2 .
Concentrations of Solutions One of the reasons that molarity is commonly used is because: M x L = moles solute and M x mL = mmol solute
Dilution of Solutions To dilute a solution, add solvent to a concentrated solution. One method to make tea “less sweet.” How fountain drinks are made from syrup. The number of moles of solute in the two solutions remains constant. The relationship M1V1 = M2V2 is appropriate for dilutions, but not for chemical reactions.
Dilution of Solutions Common method to dilute a solution involves the use of volumetric flask, pipet, and suction bulb.
Dilution of Solutions Example 3-18: If 10.0 mL of 12.0 M HCl is added to enough water to give 100. mL of solution, what is the concentration of the solution?
Dilution of Solutions Example 3-18: If 10.0 mL of 12.0 M HCl is added to enough water to give 100. mL of solution, what is the concentration of the solution?
Dilution of Solutions Example 3-19: What volume of an 18.0 M sulfuric acid is required to make 2.50 L of a 2.40 M sulfuric acid solution?
Dilution of Solutions Example 3-19: What volume of 18.0 M sulfuric acid is required to make 2.50 L of a 2.40 M sulfuric acid solution?
Using Solutions in Chemical Reactions Combine the concepts of molarity and stoichiometry to determine the amounts of reactants and products involved in reactions in solution.
Using Solutions in Chemical Reactions Example 3-20: What volume of a 0.500 M BaCl2 is required to completely react with 4.32 g of Na2SO4?
Using Solutions in Chemical Reactions Example 3-20: What volume of 0.500 M BaCl2 is required to completely react with 4.32 g of Na2SO4?
Using Solutions in Chemical Reactions Example 3-21: (a) What volume of a 0.200 M NaOH will react with 50.0 mL of a 0.200 M aluminum nitrate, Al(NO3)3?
Using Solutions in Chemical Reactions Example 3-21: (a)What volume of 0.200 M NaOH will react with 50.0 mL 0f 0.200 M aluminum nitrate, Al(NO3)3?
Using Solutions in Chemical Reactions (b) What mass of Al(OH)3 precipitates in (a)?
Using Solutions in Chemical Reactions (b)What mass of Al(OH)3 precipitates in (a)?
Using Solutions in Chemical Reactions Titrations are a method of determining the concentration of an unknown solutions from the known concentration of a solution and solution reaction stoichiometry. Requires special lab glassware Buret, pipet, and flasks Must have an indicator also
Using Solutions in Chemical Reactions Example 3-22: What is the molarity of a KOH solution if 38.7 mL of the KOH solution is required to react with 43.2 mL of a 0.223 M HCl?
Using Solutions in Chemical Reactions Example 3-22: What is the molarity of a KOH solution if 38.7 mL of the KOH solution is required to react with 43.2 mL of 0.223 M HCl?
Using Solutions in Chemical Reactions Example 3-23: What is the molarity of a barium hydroxide solution if 44.1 mL of a 0.103 M HCl is required to react with 38.3 mL of the Ba(OH)2 solution?
Using Solutions in Chemical Reactions Example 3-23: What is the molarity of a barium hydroxide solution if 44.1 mL of 0.103 M HCl is required to react with 38.3 mL of the Ba(OH)2 solution?