Chemical Reactions And Related Calculations Flashcards
0
Q
What is relative formula mass/Mr
A
The relative atomic masses of the atoms in the compounds added together
1
Q
How do you work out the relative atomic mass/Ar
A
Look at the mass number
2
Q
What are moles of a substance
A
The relative formula mass of a substance in grams is one mole of the substance
E.g iron has Ar of 56, so one mole of iron = 56g
3
Q
What is the formula for moles
A
Moles= mass in grams
—————-
Mr/Ar
4
Q
Formula for percentage mass of an element in a compound
A
Ar x number of atoms (of element)
————————————————
Mr of whole compound
5
Q
How to calculate masses in reactions
A
- write out the balanced equation
- work out the Mr - just for the bits you need
- divide to get one, multiply to get all
6
Q
What is a reversible reaction
A
Where he products of the reaction can produce the original reactants
