What is the number at the top and and the bottom of the atomic symbol?
Top: Mass number
Bottom: Atomic number
What is an isotope?
Isotopes are atoms of the same element with different numbers of neutrons
What is the relative atomic mass of an element?
This is the average value for the isotopes of the element
How do you work out the relative formula mass of a substance? (Mr)
Adding up the relative atomic mass of the atoms in the formula
What is meant by a mol of a substance?
This is the relative formula mass of a substance in grams
How do we work out the percentage of elements in a compound?
Ar (relative atomic mass) divided by Mr (relative formula mass) x 100
How do you work out the percentage yield?
Mass collected ➗maximum theoretical mass of product
What is the reason for not having the maximum yield of a product?
Some of the product may be lost when separated from the reaction mixture
Reactants reacted with other reactions
It is reversible
Why should come local manufacturers use reactions with high yields?
Using high yields in industry helps to conserve resources and reduce waste
What is the function of chromatography paper?
Chromatography paper is used to identify artificial colours
What is the function of gas chromatography? (GC-MS)
Gas chromatography is used to separate compounds in mixtures
How are compounds deprecated using gas chromatography?
The mixture is carried by the gas through a long column of packed solid particles. The individual compounds travel at different speeds through the column and come out at different times