Unit:9 Stoichiometry.
Lesson Activity:
A. Objectives:
You will learn to calculate the amount of reactants required or product formed
in a non chemical reaction.
Activity 1: How Much Can You Make?
You just got a job in charge of manufacturing for bicycle company. The production of custom-made bicycles each day. One of your responsibility is to have enough materials for each day. The major components of bicycle are bicycle frame (F),handlebars (H), seat (s), pedals (P), and wheels (W) .
Finished bicycle can be represented in this equation:F + S+ 2W + H + 2P --> FSW2HP2F + S+ 2W + H + 2P --> FSW2HP2
Seat
Pedalhandle
FrameF + S+ 2W + H + 2P --> FSW2HP2
Equation: 1F + 1S + 2W + 1H + 2P --> 1 Bike
Ratio : 1:1:2:1:2
This equation means you need one frame, one seat, two wheels, one handlebar and two pedals.
According the bicycle company, you need to produce bicycles in five-day workweek.
How many wheels should be in the plant on Monday morning to make these bicycles?____You task:
1.Using ex cell, create your own table using the formula in the above equation to estimate the number of parts you need to keep up the daily production on the above problem.
Bike
needed
2. Now create your own equation if a production design changed to tricycle. You are required to meet your clients order. Your new blue print calls for one frame, one seat, three wheels, one handlebar, and two pedals. If your company need to complete tricycle per day. Estimate the quantity of each tricycle part required. Use table to show your work and your equation.
Now let's do food stoichiometry!
3.Think about Stoichiometry's analogy in preparing a sandwich. Imagine you are in charge of fund raising activities in Gwendolyn Brooks College Prep Academy. You will estimate the quantity of sandwich ingredients you need based on your student menu survey. Cheese and turkey sandwich found to be the top choice. By using the following equation: 2B + 2T + 1C + 1L --> B2T2CL.
2 bread slices + 2 turkey slices + 1 cheese slice + 1 lettuce leaf--> 1turkey-and-cheese sandwich
+
+
+
-->
Recipe calls for 2B + 2T + 1C + 1L --> B2T2CLLettuce
pictureThe equation shows the ratio of ingredients as 2:2:1:1
Ratio
(mole ratio)Amount Needed
(amount reacted). . . . . Amount Left . . . . .
4. Can you predict the number of turkey-and -cheese sandwich can you make,if you have 45 turkey slices, 42 bread slices, and 20 cheese slices. Which of the ingredient will limit your number of turkey-and cheese sandwich. Enter your answer here.5. Using internet resources, find similar problem in stoichiometry or create your own story problem applying stoichiometry principle in non chemical reaction.
___________________________________________________________________________
Activity 2 Subscript and Superscript Analysis
Objectives:Define stoichiometry.
Describe the importance of the mole ratio in stoichiometric calculations.
Write a mole ratio relating two substances in a chemical equation.Now think like a chemist. In term of chemistry, the recipe is equivalent to chemical equation. The quantities are the number of mole an atom, mole of molecules or moles of compound, mole of ions.
Tom Stretton's web site describes, "One mole of any substance can be calculated from its formula mass. Since this is true it is absolutely essential that when you are using the mole concept that the correct formula be used. It is not enough to say "use 1 mole of nitrogen". Do we mean atomic elemental nitrogen or nitrogen gas? There is a difference! One mole of N consists of Avogadro's number of nitrogen atoms (and has a mass of 14.01 g), whereas 1 mole of N 2 consists of Avogadro's number of molecules, each molecule having two nitrogen atoms. One mole of N 2 molecules would have a mass of 2 X 14.01 g = 28.02 g.
One of the advantages of the mole concept is that it lets us think about formulas on two levels at the same time. One level is that of atoms or molecules or ions, and the other level is that of lab-sized practical quantities, such as moles and grams. Look at the equation below:
H 2O consists of 2 H + O
1 molecule of H 2O 2 atoms of H 1 atom of O
1 dozen H 2O molecules 2 dozen atoms of H 1 dozen O atoms
6.02 X 10 23 H2O molecules 12.04 X 10 23 H atoms 6.02 X 10 23 O atoms
1 mole of H 2O molecules 2 moles of H atoms 1 moles of O atoms
18.0 g of H 2O 2.0 g of H 16.0 g O atomsWhen we think about H 2O at the first level, we can easily see that a dozen of its molecules are made from two dozen atoms of H and one dozen atoms of O. However, if we switch to the more practical lab-sized level, it is just as easy to think about one mole of H 2O and to view this quantity as consisting of two moles of H and one mole of O.
The numbers in all but the last row are in the same ratio regardless of the scale, whether we deal with single particles or with moles of them. After planning an experiment at the mole level, it is easy to convert numbers of moles into corresponding masses of chemicals to meet any desired needs."Application:
Identify and analyze the ratio of each atom and molecule in terms of moles.
Chemical equation for carbon dioxide reacting with water in photosynthesis reaction as follow:
6CO2 (g) + 6H2O (l) --> C6H12O6 (s)+ 6O2 (g)
6CO2 (g) + 6H2O (l) --> C6H12O6(s) + 6O2 (g)
Carbon Dioxide
Water
Glucose
Oxygen
CO2
H2O
O
6CO 2 (g)
6H 2O Water
C6H12O 6
6O 2
6 atoms of C
12 atoms of H
6 atoms C
12 atoms of O
12 atoms of O
6 atoms of O
12 atoms H
6 molecule of CO2
6 molecules of H 2O
1 molecule of glucose or
C6H12O 61 mol O 2
6.Student task:
Write 5 balanced chemical equation and use table to identify and interpret the subscript and coefficient of the balanced chemical equation.
