Chem-101 Chapter 8: Quantities in Chemical Reactions

Flashcards based on key concepts from Chem-101 Chapter 8, covering stoichiometry, enthalpy, limiting reactants, theoretical yield, and percent yield.

What is reaction stoichiometry?

The numerical relationship between chemical quantities in a balanced chemical equation.

How can we predict the amounts of products in a chemical reaction?

By using the amounts of reactants.

In stoichiometry, what does the analogy to cooking recipes represent?

The relationship of each ingredient (reactant) to the product.

For every 2 eggs, how much flour is needed?

1 cup of flour.

If we have 3 moles of N2, how many moles of NH3 can we produce?

6 moles of NH3.

In a balanced chemical equation, what do conversion factors allow chemists to do?

Convert between moles of reactants and products.

In exothermic reactions, what happens to thermal energy?

It is emitted as heat.

What is enthalpy of reaction (∆Hrxn)?

The amount of heat gained or lost when a reaction occurs at constant pressure.

What is the limiting reactant?

The reactant that makes the least amount of product.

How do you calculate percent yield?

Percent Yield = (Actual Yield / Theoretical Yield) x 100.

What does a negative ∆Hrxn indicate?

Heat flowed from the system to the surroundings.

If 35.8 grams of C3H8 react, how is water production quantified?

By using the balanced chemical equation relating C3H8 to H2O.

What is the theoretical yield in a chemical reaction?

The amount of product that can be made based on the amount of limiting reactant.

What is required to find the heat emitted during the combustion of propane?

Use the stoichiometric ratio from the balanced equation and the heat change associated with it.

What is reaction stoichiometry?

The numerical relationship between chemical quantities in a balanced chemical equation.

How can we predict the amounts of products in a chemical reaction?

By using the amounts of reactants.

In stoichiometry, what does the analogy to cooking recipes represent?

The relationship of each ingredient (reactant) to the product.

What is enthalpy of reaction (∆Hrxn)?

The amount of heat gained or lost when a reaction occurs at constant pressure.

What does a negative ∆Hrxn indicate?

Heat flowed from the system to the surroundings