Limiting Reactants and Percent Yield Lecture Review

Flashcards covering limiting reactants, theoretical yield, and percent yield, including examples and analogies discussed in the lecture.

What chapters will the upcoming exam cover?

Chapters 3, 4, and 16.

What is the primary goal when thinking about limiting reactants in chemistry?

To predict how much of a product you would expect to make given starting concentrations, by identifying the reactant that will make the most or least amount of product.

What analogies are used to explain the concept of a limiting reactant?

The analogy of a bicycle (frames and wheels) or baking (ingredients like eggs).

In the bicycle analogy, if you have three frames and four wheels, what is the limiting reactant for making bikes?

The wheels, because you only have enough wheels for two bikes, even if you have enough frames for three.

How do you identify the limiting reactant in a chemical reaction?

It is the reactant that, when calculations are performed using stoichiometry, leads to the smaller amount of product.

What is the first step when calculating the amount of excess reactant left over?

Determine the limiting reactant.

What is the 'mole bridge' in stoichiometry?

It represents the balanced chemical equation, providing the mole-to-mole ratio to convert between quantities of different compounds.

What conversion factor allows you to go from a number of moles to a number of grams?

The molecular weight.

What is the 'theoretical yield' of a reaction?

The maximum mass (in grams) of product that is predicted to be made based on the limiting reactant.

What is 'percent yield' used to measure?

The efficiency of an experiment or chemical reaction.

What is the formula for calculating percent yield?

Percent Yield = (Actual Yield / Theoretical Yield) * 100%.

Can a percent yield ever be greater than 100%?

No, it should always be 100% or less; a number greater than 100% indicates a calculation error or experimental flaw.