C5.1 Flashcards
What is yield
The mass of the product made in a chemical reaction
What is theoretical yield
The maximum mass possible to make from a given mass of reactants.
How to work out theoretical yield
Use mole calculations (stoichometry)
What is actual yield
The actual mass of product you make in a chemical reaction
What is percentage yield
Percentage yield = actual yield/theoretical yield x 100
What are the factors that affect percentage yield
. The reactant may react in a different way than expected
. The reaction may not go to completion
. You may lose some product when separating and purifying it
What is atom economy
atom economy = sum of Mr of desired products/sum of Mr of all products x 100
What are the different factors that are considered when choosing a reaction pathway
Yield of the product
Atom economy of the reaction
Usefulness of by-products
Rate of reaction
Equilibrium position if it’s a reversible reaction
What is a by-product
Is a substance formed in a reaction in addition to the desired product. If it’s useful it’s considered in the atom economy.
How many cm cubed in a dm cubed
1000
What is the formula for concentration in (mol/dm cubed)
Concentration (mol/dm cubed) = mass of solute (mol) /volume of solution in (dm cubed)
What is the formula for concentration in (g/dm cubed)
Concentration (g/dm cubed) = mass of solute (g) /volume of solution in (dm cubed)
What is in the conical flask in a titration
In a titration you have a known volume of alkali or acid in the conical flask with an indicator such as phenolpathein.
What do you do to the tap in a titration
You need to let it flow until there is a slight colour change then add it drop by drop until it changes colour completely (whilst swirling).
What is the end point in a titration
The end point in a titration is when the alkali has been neutralised/ changed colour.
