•How many kg of lime (calcium carbonate (MM 100.0 g/mol)) is need to scrub 1.00 kg of SO2(MM 64.07 g/mol) and how much calcium sulfate is produced? 49
If 1.0 mol of H2is burned in the presence of oxygen, how many grams of O2will be consumed? A.8.0 g O2B.16 g O2C.32 g O2D.64 g O2E.We need more information508.0 g O216 g O232 g O264 g O2We need more information20%20%20%20%20%
51 • Molarity ( M ) = moles of solute per volume of solution in liters: Molarity moles of solute = Molarity = liters of solution M 6 moles of HCl 3 HCl = 2 liters of solution M
52 Demo NaHCO 3 (s) + HCl(aq) NaCl(aq) + H 2 CO 3 (aq) H 2 O(l) + CO 2 (g) We have 40 mL of 0.5 M hydrochloric acid. How much sodium bicarbonate (MM 84 g/mol) do we need to add to completely react away all of the hydrochloric acid? 1.68 g NaHCO 3
53 M 1 V 1 = M 2 V 2 Dilution
Limiting Reagent 54 (b) Write a balanced chemical reaction for sulfur dioxide reacting with oxygen to produce sulfur trioxide. SO 2 (g) + ½ O 2 (g) SO 3 (g) 2SO 2 (g) + O 2 (g) 2SO 3 (g) Assume you have the following number of molecules and draw a representation of what would happen in block (b) if the reaction goes to completion.
Limiting Reagent 55 (b) How many sulfur trioxide molecules will be produced? How many sulfur dioxide molecules will be consumed? How many oxygen molecules are consumed? What molecules is the limiting reagent? 6 6 3 SO 2
Limiting Reagent 56 • What is a limiting reagent?
Limiting Reagent: Making Sandwiches 57
58 Calculating Masses of Reactants and Products in Reactions
59 You react 10.0 g of A with 10.0 g of B. What mass of product will be produced given that the molar mass of A is 10.0 g/mol, B is 20.0 g/mol, and C is 25.0 g/mol? They react according to the equation: A + 3B 2C 8.33 g of C Limiting reagent
Limiting reagent example 60 Butene (C 4 H 8 ) and molecular oxygen are combusted. If 10.0 g of butene is reacted with 60.0 g of oxygen, how many grams of water and carbon dioxide are produced? Will either of the reactants remain after the reaction is complete? How much remains? • There are many ways to solve a limiting reagent problem. (a) The first step in most limiting reagent problems is to write a balanced chemical reagent. Write a balanced equation for the above reaction.
Limiting Reagent 61 • Which of the following reaction mixtures could produce the greatest amount of product? Each involves the reaction symbolized by the equation: 2H 2 + O 2 2H 2 O 2 moles of H 2 and 2 moles of O 2 2 moles of H 2 and 3 moles of O 2 2 moles of H 2 and 1 mole of O 2 3 moles of H 2 and 1 mole of O 2 Each produce the same amount of product.