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 Carbon disulfide reacts with oxygen to form carbon dioxide and sulfur dioxide CS2 3O2 CO2 2SO2 95 6 g CS2 76 13 g mol 1 26 mole CS2 2 mole SO2 1 CS2 2 52 mole SO2 64 065 g mole 161 g SO2 110 g O2 32 g mol O2 3 4374 mole O2 3 4374 mole O2 2 mole SO2 3 mole O2 2 29 mole SO2 64 065 g mole 147 g SO2 1 How many g of silver bromide can be formed when solutions containing 50 0 g of magnesium bromide and 100 0 g of silver nitrate are mixed together magnesium nitrate is also produced How many g of the excess reactant remain unreacted MgBr2 2AgNO3 2AgBr Mg NO3 2 CONVERT GRAMS TO MOLESSSSSSSSS 50 0 g MgBr2 184 1 g mol 0 272 mole MgBr2 0 272 mole MgBr2 2 AgBr 1 MgBr2 544 mole AgBr Limiting reactant 544 187 8 g mol 102 g AgBr 100 0 g AgNO3 196 88 g mol 0 589 mole AgNo3 0 589 mole AgNO3 2 AgBr 2AgNO3 0 589 mole AgBr 50 0 g MgBr 184 1 g mol 272 mol MgBr 272 mol MgBr 2 mol AgNO3 1 mol MgBr 544 mol AgNO3 544 mol AgNO3 169 9 g mol 92 48 g AgNO3 100 g AgNO3 92 48 g AgNO3 7 6 g AgNO3 Percent Yields from Reactions Theoretical yield is calculated by assuming that the reaction goes to completion Determined from the limiting reactant calc 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 actual yield yield 100 theoretical yield 3 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 CH 3COOH C 2 H 5OH CH 3COOC 2H 5 H 2O 4 Clicker question In a previous problem we determined that 102 g of AgBr was theoretically possible But when we did the actual experiment we only made 85 6 g of AgBr What is the yield 85 6 102 x 100 83 9 Sequential Reactions More than one reaction is required to convert starting materials into the desired products The amount of desired product from each reaction is taken as the starting material for the next reaction Starting with 10 0 g of benzene C6H6 calculate the theoretical yield of nitrobenzene C6H5NO2 and of aniline C6H5NH2 10 0 g C6H6 78 0 g mol 128 mol C6H6 1 C6H5NO2 1 C6H6 128 MOL C6H5NO2 123 G MOL 15 8 G C6H5NO2 128 MOL C6H5NO2 1 C6H5NH2 1 C6H5NO2 128 MOLE C6H5NH2 93 0 G MOL 11 9 G C6H5NH2 7 Clicker question If 6 7 g of aniline is prepared from 10 0 g of benzene what is the percentage yield 6 7 11 9 X 100 56 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 9 One common unit of concentration is mass of solute by mass of solute 100 mass of solution mass of solution mass of solute mass of solvent by mass of solute has the symbol w w 10 What mass of NaOH is required to prepare 250 0 g of solution that is 8 00 w w NaOH X g NaOH 250 0 g 8 00 g 100g x 20 0 g NaOH 11 Calculate the mass of 8 00 w w NaOH solution that contains 32 0 g of NaOH 32 0 g x g 8 100 x 400 g 12 Calculate the mass of NaOH in 300 0 mL of an 8 00 w w NaOH solution Density is 1 09 g mL 13 What volume of 12 0 w w KOH contains 40 0 g of KOH The density of the solution is 1 11 g mL 14 Concentrations of Solutions Second common unit of concentration number of moles of solute molarity number of liters of solution moles M L mmol M mL 15 Concentrations of Solutions Calculate the molarity of a solution that contains 12 5 g of sulfuric acid in 1 75 L of solution 16 Clicker question What is the molarity of a solution that contain 10 0 moles of a solute in 2 00 l of solution Determine the mass of calcium nitrate required to prepare 3 50 L of a 0 800 M Ca NO3 2 18