Bozeman Science
Multistep Reactions
In this video Paul Andersen explains how an overall chemical reaction is made up of several elementary steps. The stoichiometry of this equation can be predicted but the rate law must be measured. If the elementary steps of the reaction...
MinuteEarth
Dangerous Marshmallows?!
Burning a marshmallow can release more energy than detonating an equal mass of TNT...so why isn't a marshmallow as dangerous?
Bozeman Science
Synthesis and Decomposition Reactions
Atoms or molecules combine to form a new compound in a synthesis reaction. Examples include the addition of oxygen to magnesium metal to create magnesium oxide and the addition of carbon dioxide to water to crete carbonic acid. A combine...
Bozeman Science
Stoichiometry
In this video Paul Andersen explains how stoichiometry can be used to quantify differences in chemical reactions. The coefficients in a balanced chemical equation express the mole proportions in that reaction. These values can be used to...
Curated Video
Striking a Balance : Investigating Reaction Rate and Stoichiometry
Influence of Stoichiometry on Rate of Reaction. Rate of Reaction & Stoichiometry part 1
Curated Video
Learning the Mechanisms : Investigating the Breakdown of Ammonia and Reaction Rates
Stoichiometry role in rate formation of Nitric oxide formation. Rate of Reaction & Stoichiometry part 2
Professor Dave Explains
Calculating the Formulas of Hydrated Salts
Some ionic compounds are coordinated to a specific number of water molecules in solution. But how many? How can we find out? We can't see molecules! Whatever will we do? Something very clever, as it turns out. Take a look!
Professor Dave Explains
Limiting Regents and Percent Yield
Chemistry doesn't always work perfectly, silly. Molecules are left over when one thing runs out! Also we never get all of the products that we thought we might by doing the math. You gotta know about the limiting reagents and the percent...
Professor Dave Explains
IIT/JEE Chemistry Practice #6: Stoichiometry/Precipitation Reactions
Practice REAL problems from actual past IIT/JEE exams with Professor Dave!
Professor Dave Explains
IIT/JEE Chemistry Practice #4: Limiting Reagents
Practice REAL problems from actual past IIT/JEE exams with Professor Dave!
Professor Dave Explains
IIT/JEE Chemistry Practice #3: Empirical/Molecular Formula
Practice REAL problems from actual past IIT/JEE exams with Professor Dave!
Professor Dave Explains
Practice Problem: Balancing Equations
Who couldn't use a little practice balancing equations? If you've seen my tutorial outlining how to do this, then you're ready for four rapid fire examples to make sure you're ready to do this on your own. Give them a shot!
Professor Dave Explains
Practice Problem: ICE Box Calculations
Sometimes when we do equilibrium calculations, we have to use an ICE box. Don't worry it won't be chilly, it stands for initial, change, and equilibrium. Let's use this technique to calculate some equilibrium concentrations!
Professor Dave Explains
Practice Problem: Limiting Reagent and Percent Yield
Once we get the hang of stoichiometric calculations, we get a curve ball. Limiting reagents? Not all of the reactants will react? We might not get as much product as we expect? Let's practice identifying the limiting reagent, calculating...
Professor Dave Explains
Practice Problem: Calculating Equilibrium Concentrations
We know how to write equilibrium constant expressions for any equilibrium, and we know that they relate the equilibrium constant to the equilibrium concentrations for all of the substances in the system. Let's see if we can calculate a...
Professor Dave Explains
IIT/JEE Chemistry Practice #2: Molar Mass/Stoichiometry
Practice REAL problems from actual past IIT/JEE exams with Professor Dave!
Professor Dave Explains
IIT/JEE Chemistry Practice #10: Gas Stoichiometry
Practice REAL problems from actual past IIT/JEE exams with Professor Dave!
Professor Dave Explains
Practice Problem: Density of a Gas
If we can use the ideal gas law to find the molar mass of a gas and therefore identify the gas, what can we do with the density of a gas? Well, pretty much the same thing, it just involves one extra calculation, so let's give it a try!
Professor Dave Explains
Practice Problem: Gravimetric Analysis
What the heck is gravimetric analysis? Well let's say we want to know how much of a substance is in some mixture. We could toss it in solution and cause it to form a precipitate with some other ion in solution. We can measure the mass of...
Professor Dave Explains
Practice Problem: Empirical and Molecular Formulas
How do we know how many atoms of each element are in a particular compound? Through clever experiments! Here let's practice using percent mass information to get the empirical and molecular formulas of a particular compound.
Professor Dave Explains
Practice Problem: Titration Calculations
Titration is a way to do stoichiometry with acids and bases. The equivalence point tells us something about the moles of acid and base that are present in solution at that moment. And if we know one of those values, we can know the...
Professor Dave Explains
Practice Problem: Enthalpy of Vaporization
Can we do stoichiometry regarding phase changes? Sure! If we know how many moles of a substance we have, and the energy associated with each mole of that substance undergoing a particular phase change, we can get the energy associated...
Professor Dave Explains
Acid-Base Titration
Any introductory chemistry class will include titrations, and to do these, you have to do math. But you get to see pretty colors, too! Here's a quick run through of the stoichiometry of it all.
Professor Dave Explains
Writing Chemical Equations in Words
Sometimes we want to talk about chemistry without using fancy symbols, just with words. Shouldn't we be able to do that? Yes, we should! Here's how.