With this information and a balanced chemical reaction, you can calculate the theoretical (ideal) yield of a chemical reaction, perform the lab and compare it to an actual yield of product collected.
A useful explanation of “stoichiometry” is:
“Stoichiometry is a section of chemistry that involves using relationships between reactants and/or products in a chemical reaction to determine desired quantitative data. In Greek, stoikhein means element and metron means measure, so stoichiometry literally translated means the measure of elements. (http://chemwiki.ucdavis.edu/Analytical_Chemistry/Chemical_Reactions/Stoichiometry_and_Balancing_Reactions )
Stoichiometry can be approached a few different ways – I find that using Dimensional+ Analysis or The Factor-Label Method (discussed on 09/02/2014) is a very clear way for students to work on these problems.
Here is a 16 minute video about Stoichiometry problems. The beginning discussion of conversion factors is for the use of Dimensional Analysis in solving these problems:
2 Mg + 1 O2 à 2 MgO
2 : 1 : 2
I also point out that all of the conversion factors combine to form one big fraction. For example,
3.00 g Mg 1 mol Mg 1 mol O2 32 g O2
------------------------------------------------------------------- = 1.98 g O2
24.3 g Mg 2 mol Mg 1 mol O2
Here are some worksheets using the skills of balancing equations and stoichiometry:
This worksheet only has two problems, but it could be projected for classroom lecture use:
The page contains an overview of the skills required for stoichiometry and answers:
This worksheet with answers focuses on gas stoichiometry problems:
This post contains several pages and answers related to stoichiometry:
This posting is a good resource of stoichiometry questions and answers:
Check out the Topic List to help you to find past Blog entries. I hope it helps!
The holidays approach, so buy my lab book "Chemistry on a Budget" (or ask for it as a gift) -- it is available for $20 at amazon.com or $23 at lulu.com. It will take a few weeks to get to you, so order now!
“Chemistry on a Budget” includes the lab A Chemical Reaction that focuses on the stoichiometry of a simple reaction that provides very good results!
This book contains 13 labs using consumable materials purchased from local stores. There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.
Have a great weekend!