Quantitative Chemistry- Paper 1 Flashcards
Why might a % yield of a reaction not be 100%?
copper oxide
Some solution left behind when mixture was filtered
What’s the value of Avogadro constant?
6.02 x 10^23
What is Avogadro’s constant used for?
The number of particles in a mole.
What does the conservation of mass mean?
That during a reaction no atoms are created or destroyed so mass of reactants=mass of products
What is meant by the term limiting reactant?
When a reactant gets used up in a reaction before the rest and therefore stops the reaction.
What volume does one mole of any gas occupy at room temperature and pressure?
24dm^3
State the values of room temperature and pressure
20 degrees C
1 atm.
How do you calculate the atom economy of a reaction?
Mr of desired products/Mr of all reactants x 100
How do you calculate the % yield
mass of product made/ maximum mass of product x 100
Why do people want high % yields?
To reduce waste and extra cost.
Give 3 reasons why % yield is always less than 100%?
Not all reactants react to make a product
There may be side reactions
You lose some product when you separate it from the reaction mixture
