Amount of Substance - Percentage Yields Flashcards
What is percentage yield?
Gives us a measure of the effectiveness of a synthetic procedure
What is the equation for percentage yield?
Actual yield / theoretical yield x 100%
Why are percentage yields important?
2
Tells us what % of our reactants have been converted into products
Indicates how successful our chemical reaction has been
Is percentage yield always 100%?
Why/why not?
(4)
No
Unwanted by-products may be produced as a result of side reactions occurring
Some of the reactant may retain unreacted in the reaction vessel
Some product may be lost
Reaction may not proceed to completion as it’s in equilibrium
What does limited reagents mean?
In reactions, one chemical is usually I’m excess
The other chemical is not in excess - this is the limiting reagent and it dictates the amount of product that is produced
How can you work out which is the limiting agent?
Using the moles, molar mass, mass equation
