# Resource Topic: Stoichiometry

• ## The Mole, Molarity, and Density

• #### Creating a Stock Solution

In this activity, students use the virtual lab to create dilute solutions from a concentrated stock solution of acids or bases. They must first calculate the correct volumes of concentrated acid solution and water…

• #### Metals Density Problem

In this activity, students use the virtual lab to identify 3 unknown metals by measuring their density and comparing their measurements to the densities of known metals. In this randomized version, each student…

• ### Scenario-Based Activities

• #### Mixed Reception

###### Scenario-Based Activity

An in-class activity in which students use molar mass calculations, the scientific method and basic knowledge of chemical reactions to solve a murder mystery. The activity begins with a 5 minute introductory video,…

• #### [ChemVlab+] Powderade: Using Sports Drinks to Explore Concentration and Dilution

###### Scenario-Based Activity

In this interactive activity, students first use color to determine which drinks are the most concentrated. Next students use the Virtual Lab to create solutions whose concentration matches that of two characters…

• #### [ChemVlab+] The Factory: Using a City Water System to Explore Dilution

###### Scenario-Based Activity

In this interactive activity, students must determine whether the factories in a fictional town are adhering to the guidelines the city has established for their emissions. The challenge is that, for some factories,…

• #### [ChemVlab+] Gravimetric analysis and a closer look at drinking water

###### Scenario-Based Activity

In this interactive activity, students first learn how gravimetric analysis can be used to determine the concentration of various species in water, through a combination of particulate-level representations and…

• ### Simulations

• #### Periodic Table

###### Simulation

This simulation provides an interactive periodic table that also includes illustration of electron configurations in periodic trends. The schematic diagram to the right of the table plots the electron configurations…

• ### Tutorials

• #### The Mole

###### Tutorial

This tutorial introduces the concept of the mole and how it is used in chemistry to connect macroscopic and molecular level scales. Practice is provided on the applied definition of the mole.

• #### Solution Stoichiometry (Molarity)

###### Tutorial

This tutorial provides a quantitative overview of substances in solution and practice quantifying the amount of a substance in a solution. Guided practice in solution concentration calculations is provided.

• #### Measuring Density

###### Tutorial

This tutorial explains the definition of density and explains how to perform density measurements. Guided practice in density calculations is also provided.

• #### Significant Figures

###### Tutorial

This tutorial provides a brief review of the guides for determining how many significant figures to include when reporting your answer in a chemistry calculation. Guided practice in performing significant figures…

• #### Dimensional Analysis/Stoichiometric Conversions

###### Tutorial

This tutorial provides a brief overview of dimensional analysis, including conversion between the amount of a substance expressed in "number of molecules" and the amount of a substance expressed in "moles of molecules".

• #### Calculating Molecular Weight

###### Tutorial

This tutorial provides instruction and practice on how to calculate the molecular weight of a substance from the atomic weights given on the periodic table.

• #### Using Molecular Weight

###### Tutorial

This tutorial explains use the molecular weight to convert between the macroscopic scale (grams of a substance) and the microscopic scale (number of molecules of that substance). Guided practice performing molecular…

• #### Composition Stoichiometry

###### Tutorial

This tutorial provides instruction and practice converting between moles of a molecule and the moles of atoms that the molecule is composed of.

• #### Making a Standard Solution from Another Solution: Dilution

###### Tutorial

This tutorial begins with the concept of concentration and expands this to the concept of dilution. It then provides and overview of the calculations and procedure for performing a dilution in the laboratory. Guided…

• ### Virtual Labs

• #### Glucose Dilution Problem

###### Virtual Lab

In this activity, students use the virtual lab to create a 0.025M glucose solution from a standard 1M glucose solution. First, they calculate the correct volumes of 1M glucose solution and water to mix together…

• #### Acid Dilution Problem

###### Virtual Lab

In this activity, students use the virtual lab to create 500mL of 3M HCl solution from a concentrated stock solution of 11.6M HCl. They must first calculate the correct volumes of 11.6M HCl solution and water to…

• #### Cola and Sucrose Concentration Problem

###### Virtual Lab

In this activity, students use the virtual lab to prepare a sucrose solution for a soda recipe. They next calculate the concentration of their solution in terms of molarity, percent mass and density. Finally, they…

• #### Making Stock Solutions from Solids

###### Virtual Lab

In this activity, students use the virtual lab to create stock solutions starting from solid salts. Students must first calculate the correct amount of solid to make the solution. Next, they prepare the solution…

• #### Identifying the Unknown Metal (Metals Density Problem)

###### Virtual Lab

In this activity, students use the virtual lab to identify an unknown metal by measuring its density and comparing their measurements to the densities of known metals.

• #### Identifying an Unknown Liquid from its Density

###### Virtual Lab

In this activity students use the virtual lab to design an experiment to determine the identity of mislabeled bottles using the densities of the solutions inside.

• #### Alcohol Density Problem

###### Virtual Lab

Determine the concentration of an alcohol solution from its density.

• ## Reaction Stoichiometry and Limiting Reagents

• #### Determining Reactants and Products in a Solution of DNA

In this limiting reagents problem, students are given random volumes and concentrations of DNA solutions and are asked to predict what will remain after a reaction has occurred. Students can check their prediction…

• #### Determine the Concentration of Unknown Silver Nitrate Solution

In this limiting reagents problem, students are asked to determine the amount of silver nitrate dissolved in a solution by performing a reaction with solid NaCl. In this randomized activity, each student is given…

• #### Chemical Remediation of Arsenic

In this problem, students determine the limiting reagent in a reaction involving the remediation of arsenic from drinking water.

• #### Determining Stoichiometric Coefficients

Students use the virtual lab to determine how 4 unknown substances react with each other including their stoichiometric coefficients. In this randomized activity, each student receives a different reaction and…

• ### Scenario-Based Activities

• #### Arsenic in Drinking Water

###### Scenario-Based Activity

Set in the context of ground water contamination in Bangladesh, this stoichiometry and analytical chemistry activity examines the issues around identifying wells contaminated with arsenic. (Part of a larger online…

• #### [ChemVlab+] Bioremediation of Oil Spills

###### Scenario-Based Activity

Getting bacteria to eat oil is a powerful approach to cleaning up oil spills, and the first step is adding a bioremediation accelerator to form clumps that the bacteria will eat. In this activity, students perform…

• ### Simulations

• #### Stoichiometry Applet

###### Simulation

One of the first numerical problems encountered in introductory chemistry is that of "limiting reagents". This applet serves as a supplement to such calculations, providing imagery that helps students see beyond…

• ### Tutorials

• #### Reaction Stoichiometry

###### Tutorial

This tutorial introduces the concept of reaction stoichiometry, determining the amount of substance that is consumed or produced by a reaction. The tutorial then explains how to calculate how much of a reactant…

• #### The Stoichiometry of Product Formation and Percent Yield

###### Tutorial

This tutorial provides on overview in determining the amount of product formed by a reaction. It explains how to perform calculations involving how much product was formed in a chemical reaction and explains theoretical…

• #### Limiting Reagents

###### Tutorial

This tutorial describes how to determine the amount of each reactant that is consumed and each product that is produced in a given chemical reaction. Guided problems as well as a randomized calculation activity…

• ### Virtual Labs

• #### Gravimetric Determination of Arsenic

###### Virtual Lab

Set in the context of ground water contamination in Bangladesh, this stoichiometry and analytical chemistry activity examines the issues around identifying wells contaminated with arsenic. (Part of a larger online…

• #### Determining Stoichiometric Coefficients

###### Virtual Lab

In this activity, students use the virtual lab to determine how 4 unknown substances react with each other including their stoichiometric coefficients.

• #### Stoichiometry and Solution Preparation Problem

###### Virtual Lab

In this limiting reagents problem, students mix together solutions in different ratios in an attempt to produce a final solution that contains only 1 product.

• #### Textbook Style Limiting Reagents Problems

###### Virtual Lab

Textbook-style practice limiting reagent exercises with that can be used as a way to "predict and check" your answers using the virtual lab.

• #### Textbook Style Limiting Reagents Problem II

###### Virtual Lab

In this activity, students practice with experiments involving limiting reagents and the test their knowledge to determine the concentration of an unknown solution.

• #### Predicting DNA Concentration

###### Virtual Lab

In this limiting reagents problem, students are given specific concentrations of DNA solutions and are asked to predict what products and reactants will remain after a specific volumes are mixed and reaction has…

• #### Unknown Concentration of DNA Solution Problem

###### Virtual Lab

In this advanced limiting reagent problem, students use the virtual lab to determine the concentration of a solution of DNA by reacting it with known amounts of a fluorescent dye which binds to the DNA.

• ## Empirical Formula and Mixtures

• #### Mineral Composition

In this randomized calculation activity, students calculate the empirical formula of a compound given its elemental analysis. Step-by-step support and feedback is provided for students who need additional help.

• #### Composition Determination of a Mixture

In this activity, students calculate the percent composition of a mixture of two arsenic-containing minerals. Step-by-step support and feedback is provided for students who need additional help.

• ### Tutorials

• #### Empirical Formula Introduction

###### Tutorial

This tutorial defines empirical formula and discusses various ways in which it is used.

• #### Determining the Empirical Formula of a Compund from Its Molecular Formula

###### Tutorial

This tutorial explains how to calculate an empirical formula when given a molecular formula. Guided practice in performing empirical formula calculations from molecular weight is provided.

• #### Determining the Empirical Formula from an Elemental Analysis

###### Tutorial

This tutorial explains how to obtain a substance’s the empirical formula from an elemental analysis. It discusses how to compare the empirical formula obtained from an elemental analysis with that from a molecular…

• #### Composition of Mixtures

###### Tutorial

This tutorial explains the advanced topic of using a chemical reaction, such as burning in oxygen, to determine the relative composition of a mixture. Guided practice in performing calculations that involve a mixture…