Calculations Flashcards
1
Q
Empirical formula:
A
Simplest whole number ratio of atoms of an element in a compound.
2
Q
How do you get from atoms/molecules to moles?
A
Divide by 6.02x10^23
3
Q
How do you get from moles to grams?
A
Times by relative formula mass.
4
Q
Relative formula mass:
A
The sum of all relative atomic masses of all atoms in the formula of a substance.
5
Q
Empirical formula steps:
A
Divide masses by RAM.
Divide both by smallest number.
Write formula in symbols.
6
Q
Conservation of mass:
A
In a closed system, mass of products = mass of reactants.
7
Q
Why do some chemical reactions involve a change in mass?
A
Because one of the reactants or products is a gas. E.g. copper + oxygen -> oxygen + copper oxide.
