Maths in Chemistry - Simple unit 4 Flashcards
1
Q
What is the mass number?
A
Protons plus neutrons
2
Q
What is Ar?
A
Relative atomic mass
3
Q
How do you work out the Ar of an element?
A
Protons plus neutrons
4
Q
What is Mr?
A
Relative molecular mass
5
Q
How do you work out the Mr of a molecule?
A
Sum of all the Ar
6
Q
What is the Mr of H2O? H=1 O=16
A
1+1+16=18
7
Q
What is the Mr of Na2O? Na=23 O=16
A
23+23+16=62
8
Q
What is the Mr of MgO? Mg=24 O=16
A
24+16=40
9
Q
How do you work out the percentage of an element?
A
Mass of element/Mr times 100
10
Q
What is the equation for working out the moles of a substance?
A
Mr Mass Moles
11
Q
What are moles?
A
The Mr in grams
