Mass Calculations: How many grams of salicylic acid are needed to produce 1.80 kg of aspirin? � Balanced Equation: ?g C7 = 1.80 x 10 3 g C9 x [mol C9 /180.15g C9 ] x [1 mol C7 / 1 mol C9 ] x g C7 /mol C7 1 1 ?g C7 = 1380 grams
Mass Applications: Determining a Limiting Reagent � Does one of the reactants have fewer stoichiometrically adjusted moles than the other reactant? If so, the reactant with the smaller value is the limiting reagent. Calculation: � Divide the mass of each reactant by its respective Molar Mass and by its Stoichiometric factor from the balanced equation; then compare the results.
Thoughts to Consider How much CO 2 do you produce per gallon of gasoline (octane, d= 0.70 g/ml) when gasoline is combusted? How much CO 2 do you personally produce from driving every week?…. every month? …. every year? ….from other uses and sources? Why do people in developed nations, like the U.S., Japan & in the EU, produce tons more of CO 2 per person than people in under developed or developing nations? Does the increase in “man-made” CO 2 relate to global warming?
Greenhouse Gases: The Chemistry of Warming
What is a greenhouse gas? The sun’s energy & the molecule’s shape decide. Our atmosphere (air) is 78% nitrogen and 21% oxygen.Our atmosphere (air) is 78% nitrogen and 21% oxygen. Neither are greenhouse gases. They do not absorb infrared radiation (heat).Neither are greenhouse gases. They do not absorb infrared radiation (heat). However, H 2 O and CO 2 can absorb infrared energy. Without them earth would be very chilly.However, H 2 O and CO 2 can absorb infrared energy. Without them earth would be very chilly.
ANSWER ) )16.4 g Section 3.9 Stoichiometric Calculations: Amounts of Reactants and Products(p. 102 The balanced equation is Ca(OH) + 2HNO Ca(NO) + 2HO. Water is the other product for an acid/base reaction.
QUESTION The amount of tungsten metal, used to make many lightbulb filaments, starting with 25.0 grams of WO 3 in the following reaction was 18.0 grams. What percent yield does this represent? WO H 2 W + 3 H 2 O % 2.110% % 4.I think I may have confused one of the steps in this calculation
ANSWER Choice 3 has properly converted the initial grams of WO 3 to moles and used the mole ratio of the equation to determine the maximum moles of W that would be produced if all the WO 3 reacted (theoretical yield – 19.8 g). The division of the actual yield by the theoretical yield 100 produces the answer. Section 3.8: Stoichiometric Calculations: Amounts of Reactants and Products
Percent Yield � A reaction was conducted that theoretically would produce moles of quinine, C 20 H 24 N 2 O 2. The actual amount of isolated quinine was 780 mg. What is the percent yield of quinine? � 324 g/mol x mol = 81g = 810mg(theoretical) � % Yield = 780 mg/ 810 mg x 100 � % Yield = 96%
Mass Calculations: How many grams of salicylic acid are needed to produce 1.80 kg of aspirin if the process produces an 85.0% yield? � Balanced Equation: ?g C7 = 1.80 x 10 3 g C9 x [mol C9 /180.15g C9 ] x [1 mol C7 / 1 mol C9 ] x g C7 /mol C7 1 1 ?g C7 = 1380 grams ?g C7 = 2.12 x 10 3 g C9 x [mol C9 /180.15g C9 ] x [1 mol C7 / 1 mol C9 ] x g C7 /mol C7 ?g C7 = 1624 grams 1.80 x 10 3 g C9 /85/100 = 2.12 x 10 3 g C9 = 1380 grams / 85/100