Quantitative Chemistry Flashcards
1
Q
How to find the relative formula mass:
A
Add up the relative atomic masses together (times by the small number at the end if there is one)
2
Q
Percentage mass of an element in a compound
A
Ar x number of atoms of that element
—
3
Q
How to find the percentage mass of sodium carbonate Na2CO3
A
Find the Mr = 106
Percentage mass of sodium=43%
4
Q
Describe the law of conservation of mass:
A
The law of conservation of mass says that no atoms can be created or destroyed in a chemical reaction. Therefore, the total mass of reactants must equal the total mass of products.
5
Q
What is the Law of Conservation of mass?
A
Total mass of reactants=total mass of products
6
Q
What is relative (molecular) mass?
A
Mr= sum of (Ar)
