C.4 Quantative Chemistry Flashcards
(18 cards)
What is conservation of mass
Atoms cannot be created or destroyed
When a metal forms a metal oxide why does the mass increase
Oxygen atoms from the air have been added
When an acid reacts with a metal why does the mass decrease?
Because a gas is produced and escapes
What is relative formula mass
Sum of all relative masses of each atom in a compound
The relative atomic mass of an element compares the mass of an element with the mass of an atom of
Carbon -12
What symbol is used for Relative formula mass
Mr
What is a mole
Represents 6.022x10^23 atoms
This is avagadros constant
formula for mass, moles and mr
Mr Mol lives under the Mass
Mass= Mr*Mol
What is a limiting reactant
A reactant that does not have enough mass to react with all the product
What is the yield of a chemical reactions
The amount of useful product
What is the theoretical yeild
The yield you would expect to get in a reaction
What is the percentage yield
The amount of actual yield you produce / theoretical yield
Why is the % yield almost never 100
- Reversible reaction
- loss of product on separation
- unexpected side reactions
What is atom economy
THe amount of starting material that ends up as useful product
What is atom economy important
Economic and sustainability
How is atom economy calculated
(Mr desired/ Mr all reactants)* 100
What do moles of gases and their volumes have in common
At the same temp they occupy the same volume
What is the volume of one mole
24dm^3
