Stoichiometry

Introduction

Any chemist that whats to keep their job needs to know excactly how much of each compound to add in oder to have a complete chemical reaction occur?

In this webquest you will investigate how chemists are able to cost effectively synthesize all of the chemical compounds that make modern life possible.

Task

The world in which we live is only possible due to the fact that we are able produce a huge amount of synthetic compounds; drugs, plastics, and synthetic fibers are just a few things that are needed to make the modern world work. Not only do these chemicals need to be produced but they must be made in as cost effective way a possible. The Key to this is a process known as Stoichiometry.

In this chemquest it will be your goal to gain an understanding of the process involved in solving stoichiometry problems.

This Webquest will address the following Ma standards

5.1 Balance chemical equations by applying the laws of conservation of mass and constant composition (definite proportions).

5.3 Use the mole concept to determine number of particles and molar mass for elements and compounds.

5.4 Determine percent compositions, empirical formulas, and molecular formulas.

5.5Calculate the mass-to-mass stoichiometry for a chemical reaction.

5.6 Calculate percent yield in a chemical reaction.

Process

This webquest will have two parts; a research section where you will gain an understanding as to what stoimetry is and how it is used to determine the amount of reactants needed to produce various amounts of products. Part two will be to put this knowledge to use and solve a few stiochiometry based word problems.

PART 1

Step 1 watch the videos at the links below and take notes on the videos.

Video Links

https://www.youtube.com/watch?v=-NtsViOIRZA

https://www.youtube.com/watch?v=LQq203gyftA

Step 2 Find at least three more videos or tutorial websites that summerize the process of solving stiochiometry problems.

Step 3 Create a word document that includes the definition of stoichiometry, the URL's for the three videos or tutorials that you located on the web and a stepwise summery that explains the process of solving Mass to Mass Stoichiometry problems. These documents are to uploaded to my ASPEN page.

Part 2

Solve the following Mass to Mass Stoichiometry problems be sure to include all work and make sure that your answers are reported to the correct number of significant figures.

1. 0.95 moles of zinc metal is placed in an aqueous solution of hydrogen phosphate. How many moles of hydrogen gas are generated?

2. 50.0 grams of potassium chlorate are heated and decompose. How many moles of potassium chloride are formed?

3. Cobalt will react with oxygen and form cobalt III Oxide. Given 1.75 moles of cobalt how many grams of the product will form?

4. Aluminum metal reacts with nitrogen gas. How many grams of aluminum are needed to produce 25.0 grams of aluminum nitride?

Evaluation

	3 pts	2	1pts	0pts	Multipliers and Total Points
Define Stoichiometry	Correctly defined	Partially defined	Incorrectly Defined	Not Done	X 1 =_______
Websites	Word doc lists 3 valid URL’s	Word doc lists 2 valid URL’s	Word doc lists 1 valid URL’s	Not Done/No valid URL’s	X 1 =_______
Stoichiometry Steps	Word doc lists all 5 necessary steps to solve Stoich problems	Missing 1 step	Missing 2 or more steps	Not Done	X 2 =_______
Word Problem 1	Problem solved correctly to the correct Sig. Fig.	Problem partially solved or reported to wrong Sig. Fig.	Problem incorrectly solved	Not Done	X 2 =_______
Word Problem 2	Problem solved correctly to the correct Sig. Fig.	Problem partially solved or reported to wrong Sig. Fig.	Problem incorrectly solved	Not Done	X 2 =_______
Word Problem 3	Problem solved correctly to the correct Sig. Fig.	Problem partially solved or reported to wrong Sig. Fig.	Problem incorrectly solved	Not Done	X 2 =_______
Word Problem 4	Problem solved correctly to the correct Sig. Fig.	Problem partially solved or reported to wrong Sig. Fig.	Problem incorrectly solved	Not Done	X 2 =_______
				Total Score	________/36

Conclusion

By completing this assignment you will have increased your gerenal chemistry knowledge as well as developing an understanding of the key chemistry topic of stoichiometry. We will continue to expand on this topic as the class progresses as well as working on multiple stoichiometry based laboratory activties.

Credits

We all benefit by being generous with our work. Permission is hereby granted for other educators to copy this WebQuest, update or otherwise modify it, and post it elsewhere provided that the original author's name is retained along with a link back to the original URL of this WebQuest. On the line after the original author's name, you may add Modified by (your name) on (date). If you do modify it, please let me know and provide the new URL.

Teacher Page

This is a section where answers are provided for teachers to use

This webQuest was designed to be used by a high school chemistry class it was created to be used by a class that has previous knowledge of Signficant figures, Balancing equations, chemical reactions and other basic chemistry and algebra skills.

It is intended to address the Massachusets standards

5.1 Balance chemical equations by applying the laws of conservation of mass and constant composition (definite proportions).

5.3 Use the mole concept to determine number of particles and molar mass for elements and compounds.

5.4 Determine percent compositions, empirical formulas, and molecular formulas.

5.5Calculate the mass-to-mass stoichiometry for a chemical reaction.

5.6 Calculate percent yield in a chemical reaction.

Stoichiometry is a section of chemistry that involves using relationships between reactants and/or products in a chemical reaction to determine desired quantitative data.